Exercise 4 Page 160

When isolating x, keep in mind that dividing by a negative number reverses an inequality sign.

-3(x+7) -24

Distr

Distribute -3

-3x-21 -24

AddIneq

LHS+21 RHS+21

-3x -3

DivNegIneq

Divide by -3 and flip inequality sign

x 1

Now let's look at the given number line.

The solution set of the inequality represented by the graph is the set of all x values greater than or equal to 1. Let's write this inequality. x ≥ 1 But as we discussed, in the last step of the solution the inequality sign reversed since we divided by - 3. For us to end up at the correct solution, we have to flip the inequality sign. -3(x+7) ≤ -24