Question: What is the solution?

Solve 20*z = 32*z + 84 for z.

Answer: -7

Question: What is the solution?

Solve 72*x - 40*x = 44*x + 216 for x.

Answer: -18

Question: What is the solution?

Solve 4*r + 97 = 117 for r.

Answer: 5

Question: What is the solution?

Solve 187 + 253 = 40*l for l.

Answer:
11