Question: What is the solution?

Solve 50*z = 74*z - 216 for z.

Answer: 9

Question: What is the solution?

Solve -87*o - 954 = 56*o + 4766 for o.

Answer: -40

Question: What is the solution?

Solve -76*z + 20 = -66*z for z.

Answer: 2

Question: What is the solution?

Solve -5*d + 4*d = 5 for d.

Answer:
-5