Solving Proportions The Equation 7/(x+5) = 10/5 Explained

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In the realm of mathematics, proportions play a crucial role in establishing relationships between quantities. A proportion is essentially a statement of equality between two ratios. Understanding how to solve proportions is a fundamental skill, applicable in various fields, from everyday calculations to advanced scientific problems. In this comprehensive guide, we will delve into the intricacies of solving the proportion 7/(x+5) = 10/5, providing a step-by-step approach that will empower you to tackle similar problems with confidence.

Understanding Proportions: The Foundation of Problem-Solving

Before we embark on solving the specific proportion, it is essential to grasp the underlying concept of proportions. A proportion states that two ratios are equivalent. A ratio, in its simplest form, is a comparison between two quantities. For instance, the ratio 2:3 indicates that for every two units of the first quantity, there are three units of the second quantity. When two ratios are equal, they form a proportion. This equality allows us to establish a relationship between the quantities involved, enabling us to solve for unknown values.

Proportions are represented mathematically using the following format: a/b = c/d, where a, b, c, and d are quantities. In this equation, 'a' and 'd' are known as the extremes, while 'b' and 'c' are the means. The fundamental principle governing proportions is the cross-product property, which states that the product of the extremes is equal to the product of the means. Mathematically, this translates to a * d = b * c. This property forms the bedrock of solving proportions, as it allows us to transform the proportion into a solvable equation.

In our specific proportion, 7/(x+5) = 10/5, we have two ratios that are set equal to each other. Our goal is to determine the value of 'x' that satisfies this equality. To achieve this, we will employ the cross-product property and algebraic manipulation techniques.

Step-by-Step Solution: Unraveling the Proportion

Now that we have a firm grasp of the concept of proportions and the cross-product property, let's proceed with solving the proportion 7/(x+5) = 10/5. We will break down the solution into a series of steps, ensuring clarity and understanding at each stage.

Step 1: Applying the Cross-Product Property

The first step in solving the proportion is to apply the cross-product property. As we discussed earlier, this property states that the product of the extremes equals the product of the means. In our proportion, the extremes are 7 and 5, while the means are (x+5) and 10. Applying the cross-product property, we get:

7 * 5 = 10 * (x+5)

This step transforms the proportion into an equation, which we can then solve for 'x'.

Step 2: Simplifying the Equation

Next, we simplify the equation by performing the multiplications on both sides:

35 = 10x + 50

Now, we have a linear equation in one variable, 'x'. Our goal is to isolate 'x' on one side of the equation.

Step 3: Isolating the Variable Term

To isolate the variable term (10x), we subtract 50 from both sides of the equation:

35 - 50 = 10x + 50 - 50

This simplifies to:

-15 = 10x

Step 4: Solving for x

Finally, to solve for 'x', we divide both sides of the equation by 10:

-15 / 10 = 10x / 10

This gives us:

x = -1.5

Therefore, the solution to the proportion 7/(x+5) = 10/5 is x = -1.5.

Verification: Ensuring Accuracy

To ensure the accuracy of our solution, it is always prudent to verify our answer. We can do this by substituting the value of 'x' back into the original proportion and checking if the equality holds true. Substituting x = -1.5 into the proportion, we get:

7/(-1.5+5) = 10/5

Simplifying the left side:

7/3.5 = 10/5

2 = 2

Since the left side equals the right side, our solution x = -1.5 is verified.

Alternative Methods: Expanding Your Toolkit

While the cross-product property is the most common method for solving proportions, there are alternative approaches that can be employed. These methods can be particularly useful in specific scenarios or for gaining a deeper understanding of the underlying principles.

Method 1: Simplifying Ratios

In some cases, it may be possible to simplify the ratios in the proportion before applying the cross-product property. This can make the subsequent calculations easier. In our example, we can simplify the ratio 10/5 to 2/1. The proportion then becomes:

7/(x+5) = 2/1

Applying the cross-product property, we get:

7 * 1 = 2 * (x+5)

7 = 2x + 10

Solving for 'x', we arrive at the same solution, x = -1.5.

Method 2: Finding a Common Denominator

Another approach involves finding a common denominator for the fractions in the proportion. This allows us to eliminate the fractions and work with whole numbers. In our proportion, the common denominator for (x+5) and 5 is 5(x+5). Multiplying both sides of the proportion by this common denominator, we get:

[7/(x+5)] * 5(x+5) = (10/5) * 5(x+5)

Simplifying, we get:

35 = 10(x+5)

This equation is the same as the one we obtained using the cross-product property, and solving it will lead to the same solution, x = -1.5.

Real-World Applications: Proportions in Action

Proportions are not merely abstract mathematical concepts; they have numerous real-world applications. From scaling recipes to calculating distances on maps, proportions are indispensable tools in various fields.

Scaling Recipes

Imagine you have a recipe that serves four people, but you need to make it for ten people. Proportions can help you scale the ingredients accordingly. For instance, if the recipe calls for 2 cups of flour, you can set up a proportion to find out how much flour you need for ten servings:

2 cups / 4 servings = x cups / 10 servings

Solving this proportion will tell you the required amount of flour.

Calculating Distances on Maps

Maps use scales to represent real-world distances. A scale might indicate that 1 inch on the map corresponds to 10 miles in reality. If two cities are 3.5 inches apart on the map, you can use a proportion to calculate the actual distance between them:

1 inch / 10 miles = 3.5 inches / x miles

Solving this proportion will give you the actual distance.

Currency Conversion

When traveling abroad, you often need to convert currencies. Exchange rates fluctuate, but the underlying principle of currency conversion relies on proportions. If the exchange rate is 1 US dollar = 0.85 euros, you can use a proportion to find out how many euros you will get for a certain amount of dollars:

1 dollar / 0.85 euros = x dollars / y euros

By knowing the amount of dollars you want to convert, you can solve for the equivalent amount in euros.

Conclusion: Mastering Proportions

In this comprehensive guide, we have explored the concept of proportions and the step-by-step process of solving the proportion 7/(x+5) = 10/5. We have also delved into alternative methods and real-world applications of proportions. By mastering proportions, you equip yourself with a valuable tool for problem-solving in mathematics and beyond. Remember, practice is key to solidifying your understanding. Work through various proportion problems, and you will find yourself confidently navigating mathematical challenges.

In the realm of algebra, solving for an unknown variable is a fundamental skill. This often involves manipulating equations to isolate the variable on one side, revealing its value. In this detailed explanation, we will focus on solving the equation 7/(x+5) = 10/5 for the variable 'x'. This equation represents a proportion, which is a statement of equality between two ratios. Mastering the techniques to solve such equations is crucial for a solid foundation in algebra and its applications.

Understanding the Equation: A Proportional Relationship

The equation 7/(x+5) = 10/5 is a proportion, indicating that the ratio of 7 to (x+5) is equal to the ratio of 10 to 5. Proportions are a powerful tool for representing relationships between quantities, and they appear in various contexts, from scaling recipes to calculating distances on maps. To solve for 'x', we need to employ algebraic techniques that maintain the equality of the equation while isolating 'x'.

Before we dive into the solution, let's simplify the equation slightly. The ratio 10/5 can be simplified to 2/1, making the equation:

7/(x+5) = 2/1

This simplification will make the subsequent steps a bit easier to follow.

Step-by-Step Solution: Unveiling the Value of x

Now, let's proceed with the step-by-step solution to find the value of 'x'.

Step 1: Cross-Multiplication: A Key Technique

The most common method for solving proportions is cross-multiplication. This technique involves multiplying the numerator of the first fraction by the denominator of the second fraction, and vice versa. In our equation, this gives us:

7 * 1 = 2 * (x+5)

This step eliminates the fractions, transforming the equation into a more manageable form.

Step 2: Distributing: Expanding the Expression

Next, we need to distribute the 2 on the right side of the equation:

7 = 2x + 10

This step expands the expression, allowing us to isolate the term containing 'x'.

Step 3: Isolating the Variable Term: Moving Towards the Solution

To isolate the variable term (2x), we subtract 10 from both sides of the equation:

7 - 10 = 2x + 10 - 10

This simplifies to:

-3 = 2x

Step 4: Solving for x: The Final Step

Finally, to solve for 'x', we divide both sides of the equation by 2:

-3 / 2 = 2x / 2

This gives us:

x = -1.5

Therefore, the solution to the equation 7/(x+5) = 10/5 is x = -1.5.

Verification: Ensuring Accuracy

To ensure the accuracy of our solution, we can substitute the value of 'x' back into the original equation and check if the equality holds true. Substituting x = -1.5 into the equation, we get:

7/(-1.5+5) = 10/5

Simplifying the left side:

7/3.5 = 10/5

2 = 2

Since the left side equals the right side, our solution x = -1.5 is verified.

Alternative Approaches: Expanding Your Problem-Solving Toolkit

While cross-multiplication is a reliable method, exploring alternative approaches can enhance your problem-solving skills and provide a deeper understanding of the underlying principles.

Method 1: Simplifying Ratios First

As we mentioned earlier, simplifying ratios before applying cross-multiplication can make the calculations easier. In this case, we simplified 10/5 to 2/1. This method is particularly useful when dealing with larger numbers or complex fractions.

Method 2: Multiplying by the Least Common Denominator

Another approach involves multiplying both sides of the equation by the least common denominator (LCD) of the fractions. In our equation, the denominators are (x+5) and 5. The LCD is 5(x+5). Multiplying both sides by the LCD, we get:

[7/(x+5)] * 5(x+5) = (10/5) * 5(x+5)

Simplifying, we get:

35 = 10(x+5)

This equation is the same as the one we obtained using cross-multiplication, and solving it will lead to the same solution, x = -1.5.

Potential Pitfalls: Avoiding Common Errors

When solving equations, it's crucial to be mindful of potential pitfalls that can lead to incorrect solutions. Here are some common errors to avoid:

Error 1: Incorrect Distribution

When distributing, ensure that you multiply the term outside the parentheses by every term inside the parentheses. For example, in the step 2 * (x+5), you must multiply 2 by both 'x' and 5.

Error 2: Incorrectly Combining Like Terms

When combining like terms, make sure you are adding or subtracting terms that have the same variable and exponent. For instance, you can combine 2x and 3x, but you cannot combine 2x and 3.

Error 3: Dividing by Zero

Dividing by zero is undefined in mathematics. Always check for solutions that would make the denominator of a fraction equal to zero, and exclude those solutions.

Real-World Connections: Applying Algebraic Skills

The ability to solve equations is not limited to the classroom; it has numerous real-world applications. From calculating the trajectory of a projectile to designing structures, algebraic skills are essential in various fields.

Example 1: Calculating Fuel Efficiency

If a car travels 300 miles on 10 gallons of fuel, you can set up an equation to find the fuel efficiency (miles per gallon):

300 miles / 10 gallons = x miles / 1 gallon

Solving this equation will give you the fuel efficiency of the car.

Example 2: Determining Mixture Ratios

In chemistry, you might need to determine the ratio of two substances in a mixture. If you want to create a solution that is 20% acid, you can use equations to calculate the amount of acid and water needed.

Example 3: Financial Calculations

Algebraic equations are used extensively in finance, from calculating interest on loans to determining investment returns. Understanding how to solve equations is crucial for making informed financial decisions.

Conclusion: Mastering Equation Solving

In this detailed explanation, we have explored the step-by-step process of solving the equation 7/(x+5) = 10/5 for 'x'. We have also discussed alternative approaches, potential pitfalls, and real-world applications of equation solving. By mastering these techniques, you will strengthen your algebraic foundation and enhance your problem-solving abilities. Remember, consistent practice and attention to detail are key to success in algebra.

In the domain of mathematics, proportions serve as a cornerstone for solving a myriad of problems involving ratios and relationships between quantities. A proportion, at its essence, is a declaration of equality between two ratios. This fundamental concept finds applications across diverse fields, ranging from everyday calculations to complex scientific endeavors. In this guide, we will dissect various techniques for solving proportions, using the example 7/(x+5) = 10/5 as a central illustration.

Understanding the Essence of Proportions: The Foundation for Problem-Solving

Before delving into the intricacies of solving proportions, it is imperative to grasp the underlying concept. A proportion asserts that two ratios are equivalent. A ratio, in its simplest form, embodies a comparison between two quantities. For instance, the ratio 3:4 signifies that for every three units of the first quantity, there are four units of the second quantity. When two ratios are deemed equal, they constitute a proportion. This equality empowers us to establish a relationship between the quantities involved, enabling us to solve for unknown values.

Proportions are mathematically represented as follows: a/b = c/d, where a, b, c, and d denote quantities. Within this equation, 'a' and 'd' are termed the extremes, while 'b' and 'c' are designated as the means. The cornerstone principle governing proportions is the cross-product property, which posits that the product of the extremes is congruent to the product of the means. Mathematically, this translates to a * d = b * c. This property serves as the bedrock for solving proportions, facilitating the transformation of the proportion into a solvable equation.

In our illustrative proportion, 7/(x+5) = 10/5, we encounter two ratios equated to each other. Our objective is to ascertain the value of 'x' that satisfies this equality. To achieve this, we will leverage the cross-product property and algebraic manipulation techniques.

Method 1: The Cross-Product Property: A Versatile Technique

The cross-product property stands as the most widely employed technique for solving proportions. Its simplicity and efficacy render it a go-to method for a wide spectrum of proportion problems. As elucidated earlier, this property stipulates that the product of the extremes equals the product of the means. Let's apply this method to our example proportion, 7/(x+5) = 10/5.

Step 1: Applying the Cross-Product Property

We commence by applying the cross-product property:

7 * 5 = 10 * (x+5)

This transforms the proportion into an equation ripe for solving.

Step 2: Simplifying the Equation

Next, we simplify the equation by executing the multiplications on both sides:

35 = 10x + 50

We now possess a linear equation in one variable, 'x'. Our objective is to isolate 'x' on one side of the equation.

Step 3: Isolating the Variable Term

To isolate the variable term (10x), we subtract 50 from both sides of the equation:

35 - 50 = 10x + 50 - 50

This simplifies to:

-15 = 10x

Step 4: Solving for x

Finally, to solve for 'x', we divide both sides of the equation by 10:

-15 / 10 = 10x / 10

This yields:

x = -1.5

Thus, the solution to the proportion 7/(x+5) = 10/5 is x = -1.5.

Method 2: Simplifying Ratios: A Prelude to Solving

In certain instances, simplifying the ratios within the proportion prior to applying the cross-product property can streamline the calculations. This approach can be particularly advantageous when dealing with larger numbers or fractions. Let's revisit our example proportion, 7/(x+5) = 10/5.

Step 1: Simplifying the Ratio

We observe that the ratio 10/5 can be simplified to 2/1. Substituting this simplified ratio into the proportion, we obtain:

7/(x+5) = 2/1

Step 2: Applying the Cross-Product Property

Now, we apply the cross-product property:

7 * 1 = 2 * (x+5)

Step 3: Simplifying and Solving

We proceed to simplify and solve the equation, mirroring the steps outlined in Method 1, ultimately arriving at the same solution, x = -1.5.

Method 3: Finding a Common Denominator: An Alternative Perspective

Another viable technique for solving proportions involves identifying a common denominator for the fractions within the proportion. This approach enables us to eliminate the fractions, thereby simplifying the equation. Let's apply this method to our example proportion, 7/(x+5) = 10/5.

Step 1: Identifying the Common Denominator

The common denominator for the fractions 7/(x+5) and 10/5 is 5(x+5). We multiply both sides of the proportion by this common denominator:

[7/(x+5)] * 5(x+5) = (10/5) * 5(x+5)

Step 2: Simplifying the Equation

Simplifying the equation, we get:

35 = 10(x+5)

Step 3: Solving for x

Expanding and solving the equation, we arrive at the same solution, x = -1.5.

Verification: Ensuring Solution Accuracy

Irrespective of the technique employed, it is prudent to verify the solution obtained. This can be achieved by substituting the calculated value of 'x' back into the original proportion. If the equation holds true, then the solution is deemed accurate. Substituting x = -1.5 into the proportion 7/(x+5) = 10/5, we get:

7/(-1.5+5) = 10/5

Simplifying:

7/3.5 = 2

2 = 2

Since the equation holds true, our solution x = -1.5 is verified.

Real-World Applications: Proportions in Action

Proportions are not confined to the realm of abstract mathematics; they manifest in a plethora of real-world scenarios. From scaling recipes to determining distances on maps, proportions serve as indispensable tools across diverse fields.

Scaling Recipes

Imagine you possess a recipe designed to serve six individuals, but you need to adapt it for ten individuals. Proportions can facilitate the scaling of ingredients accordingly. For instance, if the recipe calls for 1.5 cups of flour, you can establish a proportion to ascertain the requisite amount of flour for ten servings:

  1. 5 cups / 6 servings = x cups / 10 servings

Solving this proportion will unveil the necessary quantity of flour.

Calculating Distances on Maps

Maps employ scales to represent real-world distances. A scale might stipulate that 1 inch on the map corresponds to 25 miles in reality. If two cities are 4.2 inches apart on the map, you can leverage a proportion to compute the actual distance between them:

1 inch / 25 miles = 4.2 inches / x miles

Solving this proportion will furnish you with the actual distance.

Currency Conversion

When traversing international borders, currency conversion becomes a necessity. Exchange rates, albeit fluctuating, adhere to the principles of proportions. If the exchange rate is 1 US dollar = 0.92 euros, you can employ a proportion to determine the euro equivalent of a given dollar amount:

1 dollar / 0.92 euros = x dollars / y euros

By specifying the dollar amount for conversion, you can solve for the corresponding euro amount.

Conclusion: Mastering the Art of Solving Proportions

In this comprehensive guide, we have traversed the landscape of techniques for solving proportions, utilizing the example 7/(x+5) = 10/5 as a central reference point. We have explored the cross-product property, simplifying ratios, and finding a common denominator. Furthermore, we have underscored the significance of verification and illuminated the real-world applications of proportions. By mastering these techniques, you will fortify your mathematical prowess and enhance your problem-solving acumen. Remember, consistent practice is paramount to proficiency. Engage with a diverse array of proportion problems, and you will cultivate the confidence to navigate mathematical challenges with aplomb.