# Lesson 9

Dealing with Negative Numbers

Let’s show that doing the same to each side works for negative numbers too.

### Problem 1

Solve each equation.

- \(4x=\text-28\)
- \(x-\text-6=\text-2\)
- \(\text-x+4=\text-9\)
- \(\text-3x+7=1\)
- \(25x+\text-11=\text-86\)

### Problem 2

Here is an equation \(2x+9=\text-15\). Write three different equations that have the same solution as \(2x+9=\text-15\). Show or explain how you found them.

### Problem 3

Select **all** the equations that match the diagram.

A:

\(x+5=18\)

B:

\(18\div3=x+5\)

C:

\(3(x+5)=18\)

D:

\(x+5 = \frac13\boldcdot 18\)

E:

(From Unit 3, Lesson 3.)
\(3x+5=18\)

### Problem 4

There are 88 seats in a theater. The seating in the theater is split into 4 identical sections. Each section has 14 red seats and some blue seats.

- Draw a tape diagram to represent the situation.
- What unknown amounts can be found by by using the diagram or reasoning about the situation?

### Problem 5

Match each story to an equation.