Ineed on these two! can annoying explain?

You are solving the two equations for x.

9.

r = 4 + 7x - sx

We need to solve for x. x is only found in the right side. First, just flip the sides to find x only in the left side.

4 + 7x - sx = r

We want all terms with x on the left side, and all terms without x on the right side. Now we subtract 4 from both sides.

7x - sx = r - 4

Factor x in left side.

x(7 - s) = r - 4

Divide both sides by 7 - s.

12.

3z + 8 = 12 + 3x - z

Since x is only in the right side, flip the sides.

12 + 3x - z = 3z + 8

We need to isolate x in the left side, so subtract 12 from both sides and add z to both sides.

3x = 3z + 8 - 12 + z

3x = 4z - 4

Divide both sides by 3.

your answer is d 2,500

step-by-step explanation:

i believe it's a.

i'm not sure on this one, most likely correct.