Help me finish this geometry proof

Part A: 2 - 10

The 5 is the width in metres, the x is the extension in metres, and the 8 is the length in metres.

Step-by-step explanation:

5(x + 8) Distribute the properties first. (5)x +8(5)

Then multiply them. 5x + 40.

Next we want to isolate x, so we will subtract 40 to cancel out the +40. We do this on both sides to balance it.

5x + 40 = 0

5x + 40 - 40 = 0 - 40

5x = -40

Next we will divide by 5 to cancel out the multiply by 5.

5x/5 = -40/5

x = -8

So an equivalent expression would be anything that equals an answer of -8, such as 2 - 10.