Question: What is the solution?

Solve -50*z - 234 - 162 = -6*z for z.

Answer: -9

Question: What is the solution?

Solve 171 + 93 = -17*u + 61*u for u.

Answer: 6

Question: What is the solution?

Solve 429*a - 16 - 12 = 415*a for a.

Answer: 2

Question: What is the solution?

Solve -1046*r - 3442 = 386*r + 3718 for r.

Answer:
-5