Isolate the Variable in the First Inequality

Oct 13, 2025 by wbrum.org 127 views

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Introduction

Compound inequalities are a combination of two or more inequalities joined by the words "and" or "or." In this article, we will focus on solving a compound inequality of the form $a \leq x \leq b$ or $c \geq x \geq d.$ We will use the given compound inequality $5x + 7 \leq -3 \quad \text{OR} \quad 3x - 4 \geq 11$ to demonstrate the steps involved in solving such inequalities.

Step 1: Isolate the Variable in Each Inequality

To solve the compound inequality, we need to isolate the variable $x$ in each inequality. Let's start with the first inequality $5x + 7 \leq -3.$

Isolate the Variable in the First Inequality

Subtract 7 from both sides of the inequality:

5x + 7 - 7 \leq -3 - 7

This simplifies to:

5x \leq -10

Next, divide both sides of the inequality by 5:

\frac{5x}{5} \leq \frac{-10}{5}

This simplifies to:

x \leq -2

Isolate the Variable in the Second Inequality

Now, let's isolate the variable $x$ in the second inequality $3x - 4 \geq 11.$

Add 4 to both sides of the inequality:

3x - 4 + 4 \geq 11 + 4

This simplifies to:

3x \geq 15

Next, divide both sides of the inequality by 3:

\frac{3x}{3} \geq \frac{15}{3}

This simplifies to:

x \geq 5

Step 2: Write the Solution as a Compound Inequality

Now that we have isolated the variable $x$ in each inequality, we can write the solution as a compound inequality. Since the compound inequality is of the form $a \leq x \leq b$ or $c \geq x \geq d,$ we can write the solution as:

x \leq -2 \quad \text{OR} \quad x \geq 5

Conclusion

In this article, we have demonstrated the steps involved in solving a compound inequality of the form $a \leq x \leq b$ or $c \geq x \geq d.$ We used the given compound inequality $5x + 7 \leq -3 \quad \text{OR} \quad 3x - 4 \geq 11$ to illustrate the process. By isolating the variable $x$ in each inequality and writing the solution as a compound inequality, we arrived at the solution $x \leq -2 \quad \text{OR} \quad x \geq 5.$

Final Answer

The final answer is:

$x \leq -2 \quad \text{OR} \quad x \geq 5$

This is the correct solution to the compound inequality $5x + 7 \leq -3 \quad \text{OR} \quad 3x - 4 \geq 11.$

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Introduction

Compound inequalities are a combination of two or more inequalities joined by the words "and" or "or." In this article, we will address some of the most frequently asked questions about compound inequalities, including how to solve them, how to write the solution, and how to interpret the results.

Q: What is a compound inequality?

A compound inequality is a combination of two or more inequalities joined by the words "and" or "or." For example, $x \leq 2$ and $x \geq 1$ is a compound inequality, while $x \leq 2$ or $x \geq 1$ is also a compound inequality.

Q: How do I solve a compound inequality?

To solve a compound inequality, you need to isolate the variable in each inequality and then write the solution as a compound inequality. For example, if you have the compound inequality $x \leq 2$ or $x \geq 1$ , you would first isolate the variable in each inequality:

$x \leq 2$ becomes $x \leq 2$
$x \geq 1$ becomes $x \geq 1$

Then, you would write the solution as a compound inequality:

x \leq 2 \quad \text{OR} \quad x \geq 1

Q: How do I write the solution to a compound inequality?

To write the solution to a compound inequality, you need to isolate the variable in each inequality and then write the solution as a compound inequality. For example, if you have the compound inequality $5x + 7 \leq -3$ or $3x - 4 \geq 11$ , you would first isolate the variable in each inequality:

$5x + 7 \leq -3$ becomes $x \leq -2$
$3x - 4 \geq 11$ becomes $x \geq 5$

Then, you would write the solution as a compound inequality:

x \leq -2 \quad \text{OR} \quad x \geq 5

Q: How do I interpret the results of a compound inequality?

To interpret the results of a compound inequality, you need to understand what the solution means. For example, if the solution to a compound inequality is $x \leq 2$ or $x \geq 1$ , it means that the value of $x$ can be any number less than or equal to 2, or any number greater than or equal to 1.

Q: What are some common mistakes to avoid when solving compound inequalities?

Some common mistakes to avoid when solving compound inequalities include:

Not isolating the variable in each inequality
Not writing the solution as a compound inequality
Not understanding the meaning of the solution

Q: How do I check my work when solving compound inequalities?

To check your work when solving compound inequalities, you can use the following steps:

Plug in a value of $x$ that satisfies the solution to each inequality
Check that the value of $x$ satisfies both inequalities
If the value of $x$ satisfies both inequalities, then the solution is correct

Conclusion

In this article, we have addressed some of the most frequently asked questions about compound inequalities, including how to solve them, how to write the solution, and how to interpret the results. By following the steps outlined in this article, you can become more confident in your ability to solve compound inequalities and understand the meaning of the results.

Final Answer

The final answer is:

$x \leq -2 \quad \text{OR} \quad x \geq 5$

This is the correct solution to the compound inequality $5x + 7 \leq -3$ or $3x - 4 \geq 11.$