Solving: $16 rac{3}{9}-10 rac{\sqrt{2}}{5}$ | Math Discussion

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Hey guys! Today, we're diving into solving the mathematical expression 1639โˆ’102516 \frac{3}{9}-10 \frac{\sqrt{2}}{5}. This problem combines mixed fractions and irrational numbers, which might seem a bit tricky at first, but don't worry, we'll break it down step by step. This article aims to provide a comprehensive, SEO-optimized guide to help you understand every aspect of this calculation. We'll cover the basics, tackle the complexities, and ensure you grasp the underlying concepts. So, let's get started!

Understanding the Basics

Before we jump into the solution, let's quickly recap the foundational concepts we'll be using. First, we have mixed fractions. A mixed fraction is a combination of a whole number and a proper fraction (where the numerator is less than the denominator). In our expression, 163916 \frac{3}{9} is a mixed fraction. To work with it effectively, we need to convert it into an improper fraction. An improper fraction is one where the numerator is greater than or equal to the denominator. Converting mixed fractions to improper fractions makes arithmetic operations much easier.

Next, we have the term 102510 \frac{\sqrt{2}}{5}. This includes an irrational number, specifically 2\sqrt{2}. Irrational numbers cannot be expressed as a simple fraction (a/b) where a and b are integers. They have non-repeating, non-terminating decimal representations. Dealing with irrational numbers often involves keeping them in their radical form or approximating them to a certain number of decimal places for practical calculations. In this case, we will keep it in radical form to maintain precision until the final steps.

Finally, we need to remember the basic arithmetic operations: subtraction, multiplication, and division. These operations are the backbone of solving any mathematical expression. In this problem, we'll primarily be using subtraction after simplifying the terms involved. Make sure you're comfortable with these basics before moving forward, as they're crucial for understanding the solution.

Converting Mixed Fractions

Let's start by converting the mixed fraction 163916 \frac{3}{9} into an improper fraction. The formula to convert a mixed fraction abca \frac{b}{c} to an improper fraction is:

(aร—c)+bc\frac{(a \times c) + b}{c}

Applying this to our mixed fraction 163916 \frac{3}{9}, we get:

(16ร—9)+39=144+39=1479\frac{(16 \times 9) + 3}{9} = \frac{144 + 3}{9} = \frac{147}{9}

So, 163916 \frac{3}{9} is equivalent to 1479\frac{147}{9}. We can further simplify this fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 3:

147รท39รท3=493\frac{147 \div 3}{9 \div 3} = \frac{49}{3}

Thus, the simplified improper fraction is 493\frac{49}{3}.

Dealing with the Second Term

Now let's look at the second term, 102510 \frac{\sqrt{2}}{5}. This term involves an irrational number, 2\sqrt{2}. We will keep 2\sqrt{2} as is for now and focus on simplifying the fraction. We can rewrite 102510 \frac{\sqrt{2}}{5} as a single term by multiplying 10 by 25\frac{\sqrt{2}}{5}. This gives us:

10ร—25=102510 \times \frac{\sqrt{2}}{5} = \frac{10\sqrt{2}}{5}

We can simplify this fraction by dividing both the numerator and the denominator by their greatest common divisor, which is 5:

102รท55รท5=221=22\frac{10\sqrt{2} \div 5}{5 \div 5} = \frac{2\sqrt{2}}{1} = 2\sqrt{2}

So, the simplified form of 102510 \frac{\sqrt{2}}{5} is 222\sqrt{2}. Now we have both terms in a simplified form, making it easier to perform the subtraction.

Step-by-Step Solution

Now that we have simplified both parts of the expression, we can proceed with the subtraction. Our expression now looks like this:

493โˆ’22\frac{49}{3} - 2\sqrt{2}

Since 493\frac{49}{3} is a rational number and 222\sqrt{2} is an irrational number, we cannot combine them directly as they are. The best we can do is express the result in this form or approximate the value of 222\sqrt{2} to a decimal.

To approximate the value, we know that 2โ‰ˆ1.414\sqrt{2} \approx 1.414. Therefore:

22โ‰ˆ2ร—1.414=2.8282\sqrt{2} \approx 2 \times 1.414 = 2.828

Now we can subtract this approximation from 493\frac{49}{3}. First, let's convert 493\frac{49}{3} to a decimal:

493=16.333...\frac{49}{3} = 16.333...

Now we subtract the approximation of 222\sqrt{2}:

16.333...โˆ’2.828=13.505...16.333... - 2.828 = 13.505...

So, the approximate value of the expression is 13.50513.505.

Combining Rational and Irrational Numbers

It's important to understand why we can't directly combine 493\frac{49}{3} and 222\sqrt{2}. The reason lies in the nature of rational and irrational numbers. A rational number can be expressed as a fraction pq\frac{p}{q}, where p and q are integers and q is not zero. An irrational number, on the other hand, cannot be expressed in this form. When we perform operations like addition or subtraction between rational and irrational numbers, the result remains in a form that keeps the rational and irrational parts separate.

In our case, 493\frac{49}{3} is a rational number, and 222\sqrt{2} is an irrational number. When we subtract them, we can't simplify it into a single rational number. The result is expressed as the difference between a rational number and an irrational number, which is the most simplified form we can achieve without approximation.

Alternative Representation

While we approximated the value to get a decimal answer, another way to represent the solution is by keeping it in its exact form. The exact form of the solution is:

493โˆ’22\frac{49}{3} - 2\sqrt{2}

This representation is precise and doesn't involve any rounding errors. Depending on the context and the required level of precision, this might be the preferred way to express the answer. For instance, in advanced mathematical calculations or proofs, keeping the exact form is often necessary to avoid introducing errors.

Why Exact Forms Matter

Using exact forms in mathematics is crucial for maintaining accuracy and avoiding the accumulation of rounding errors. When we approximate irrational numbers like 2\sqrt{2}, we introduce a degree of inaccuracy. If we use this approximated value in further calculations, the errors can propagate and lead to significantly different results. Keeping the exact form ensures that our calculations remain precise throughout the process.

For example, consider a scenario where you need to square the result of our expression. If you use the approximated value of 13.50513.505, the square will be different from the square of the exact expression (493โˆ’22)2\left(\frac{49}{3} - 2\sqrt{2}\right)^2. The difference might seem small, but in complex calculations, these small differences can add up and affect the final outcome.

Common Mistakes to Avoid

When dealing with expressions like this, there are a few common mistakes that students often make. Let's go through them so you can avoid these pitfalls:

  1. Incorrectly Converting Mixed Fractions: One common mistake is messing up the conversion of mixed fractions to improper fractions. Remember, you need to multiply the whole number by the denominator and then add the numerator. For example, for 163916 \frac{3}{9}, it's (16ร—9)+3(16 \times 9) + 3, not 16+(3ร—9)16 + (3 \times 9).
  2. Misunderstanding Irrational Numbers: Another mistake is trying to combine rational and irrational numbers directly. You can't simply add or subtract them like regular fractions. Always keep the irrational part separate unless you are approximating to a decimal.
  3. Rounding Too Early: Rounding numbers too early in the calculation can lead to significant errors in the final result. If you need to approximate, do it at the very end of the calculation to maintain maximum precision.
  4. Forgetting to Simplify: Always simplify fractions and expressions as much as possible before performing operations. This makes the calculations easier and reduces the chances of making mistakes.

Best Practices for Accuracy

To ensure accuracy in your calculations, follow these best practices:

  • Double-Check Your Work: Always review your steps to catch any errors in calculations or conversions.
  • Use Exact Forms When Possible: Keep irrational numbers and fractions in their exact forms until the final step, if approximation is necessary.
  • Simplify Before Operating: Simplify fractions and expressions before performing addition, subtraction, multiplication, or division.
  • Understand the Properties of Numbers: Be clear about the differences between rational and irrational numbers and how they interact in mathematical operations.

Conclusion

So, guys, we've successfully tackled the mathematical expression 1639โˆ’102516 \frac{3}{9}-10 \frac{\sqrt{2}}{5}. We started by simplifying each term, converting the mixed fraction to an improper fraction, and dealing with the irrational number. We learned that the exact form of the solution is 493โˆ’22\frac{49}{3} - 2\sqrt{2}, and we also approximated the value to 13.50513.505. Remember, the key is to understand the basics, avoid common mistakes, and follow best practices for accuracy. I hope this guide has been helpful, and you now feel more confident in solving similar problems!

By breaking down the problem into smaller steps and understanding the underlying concepts, you can tackle even the most complex mathematical expressions. Keep practicing, and you'll become a pro in no time! If you have any questions or want to discuss other math problems, feel free to drop a comment below. Happy solving!