Solving Inequalities A Step-by-Step Guide To Solve 2 ≥ -1/8 Y + 12

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Have you ever stumbled upon an inequality and felt a bit lost on how to solve it? Don't worry, you're not alone! Inequalities might seem intimidating at first, but with a systematic approach, they become quite manageable. In this guide, we'll tackle the inequality 218y+122 \,\geq\,-\frac{1}{8} y + 12 step by step, ensuring you grasp the underlying concepts along the way. So, grab your pencils, and let's dive in!

Understanding Inequalities

Before we jump into solving our specific inequality, let's take a moment to understand what inequalities are all about. Unlike equations, which state that two expressions are equal, inequalities express a relationship where one expression is greater than, less than, greater than or equal to, or less than or equal to another expression. The symbols that represent these relationships are:

  • >> (greater than)
  • << (less than)
  • \geq (greater than or equal to)
  • \leq (less than or equal to)

Think of inequalities as a range of possible solutions rather than a single value. For example, x>5x > 5 means that xx can be any number greater than 5, but not 5 itself. This concept is crucial when interpreting the solutions we'll find later.

Step-by-Step Solution

Now, let's get our hands dirty and solve the inequality 218y+122 \geq -\frac{1}{8} y + 12. Our goal is to isolate yy on one side of the inequality, just like we would do with an equation. Here's how we'll do it:

Step 1: Isolate the Term with y

The first step is to get the term containing yy by itself on one side of the inequality. In our case, that's the term 18y-\frac{1}{8}y. To do this, we need to get rid of the +12+12 that's hanging out on the right side. We can achieve this by subtracting 12 from both sides of the inequality. Remember, whatever we do to one side, we must do to the other to maintain the balance.

218y+122 \geq -\frac{1}{8} y + 12

Subtract 12 from both sides:

21218y+12122 - 12 \geq -\frac{1}{8} y + 12 - 12

This simplifies to:

1018y-10 \geq -\frac{1}{8} y

Step 2: Get Rid of the Fraction

Fractions can sometimes make things look more complicated than they are. To simplify our inequality further, let's get rid of the fraction 18-\frac{1}{8} that's multiplying yy. We can do this by multiplying both sides of the inequality by the reciprocal of 18-\frac{1}{8}, which is 8-8.

1018y-10 \geq -\frac{1}{8} y

Multiply both sides by -8:

10(8)18y(8)-10 \cdot (-8) \leq -\frac{1}{8} y \cdot (-8)

Important Note: When we multiply or divide both sides of an inequality by a negative number, we must flip the direction of the inequality sign. This is a crucial rule to remember! Since we're multiplying by -8, we change \geq to \leq.

This gives us:

80y80 \leq y

Step 3: Rewrite the Inequality (Optional)

While 80y80 \leq y is a perfectly valid solution, it's often more intuitive to read the inequality with the variable on the left side. We can simply rewrite the inequality by flipping it around, ensuring that the inequality sign still points in the correct direction.

80y80 \leq y is the same as y80y \geq 80

Interpreting the Solution

So, what does y80y \geq 80 actually mean? It means that yy can be any number that is greater than or equal to 80. In other words, 80 is the minimum value that yy can take, but it can also be any number larger than 80.

To visualize this, you can think of a number line. The solution to the inequality would be represented by a closed circle (or a filled-in dot) at 80, indicating that 80 is included in the solution, and an arrow extending to the right, representing all the numbers greater than 80.

Common Mistakes to Avoid

When solving inequalities, there are a few common pitfalls that students often encounter. Being aware of these mistakes can help you avoid them:

  1. Forgetting to Flip the Inequality Sign: As we mentioned earlier, when you multiply or divide both sides of an inequality by a negative number, you must flip the direction of the inequality sign. This is perhaps the most common mistake, so always double-check!
  2. Incorrectly Distributing: If you have a term multiplying a group of terms within parentheses, make sure you distribute it correctly to each term inside. For example, if you had 2(x+3)4-2(x + 3) \geq 4, you would need to distribute the -2 to both xx and 3.
  3. Combining Unlike Terms: Just like in equations, you can only combine like terms in inequalities. For example, you can combine 3x3x and 5x5x to get 8x8x, but you can't combine 3x3x and 5.
  4. Misinterpreting the Solution: Make sure you understand what the solution to the inequality actually means. For example, if you get x<4x < 4, that means xx can be any number less than 4, but not 4 itself.

Practice Makes Perfect

The best way to master solving inequalities is to practice! Try working through various examples, gradually increasing the complexity. You can find plenty of practice problems in textbooks, online resources, and worksheets. The more you practice, the more confident you'll become in your ability to solve inequalities.

Real-World Applications

Inequalities aren't just abstract mathematical concepts; they have numerous real-world applications. Here are a few examples:

  • Budgeting: You might use inequalities to determine how much you can spend on groceries each week while staying within your budget.
  • Speed Limits: Speed limits are expressed as inequalities (e.g., the speed must be less than or equal to 65 mph).
  • Temperature Ranges: Weather forecasts often give temperature ranges, which can be represented as inequalities (e.g., the temperature will be between 70 and 80 degrees Fahrenheit).
  • Dosage Calculations: In medicine, inequalities are used to determine safe dosage ranges for medications.

Conclusion

Solving inequalities is a fundamental skill in mathematics with wide-ranging applications. By understanding the basic principles and practicing regularly, you can confidently tackle any inequality that comes your way. Remember the key steps: isolate the variable, pay attention to negative signs, and interpret the solution correctly. So, keep practicing, and you'll become an inequality-solving pro in no time!

By following this comprehensive guide, you should now have a solid understanding of how to solve the inequality 218y+122 \geq -\frac{1}{8} y + 12 and inequalities in general. Remember to practice regularly and apply these skills to real-world problems to truly master the concept. Happy solving, guys!