Big Ideas Math: Modeling Real Life, Grade 7
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Exercise 44 Page 175

What can you do to isolate a variable in an inequality?

Solution: x> 5 13
Graph:

Practice makes perfect
We can recall that Inequalities can be solved in the same way as equations, by performing inverse operations on both sides until the variable is isolated. The only difference is that when we divide or multiply by a negative number, we should reverse the inequality sign. We can consider our inequality. 3x+4>16 First, we can use the Subtraction Property of Equality. We can do so by subtracting 4 from both sides of the inequality.
3x+4>16
3x+4-4>16-4
3x>16
Next, we can use the Division Property of Inequality. We can do so by dividing both sides of the inequality by 3. Let's do it!
3x>16
3x/3>16/3
Simplify left-hand side
3/3x>16/3
1x>16/3
x>16/3
x>5 13
The above tells us that all values of x that are greater than 5 13 will satisfy the inequality. Below we demonstrate the inequality by graphing the solution set on a number line. Notice that x cannot equal 5 130, which we show with an open circle on the number line.