Question: What is the solution?

Solve 460 = -17*r + 681 for r.

Answer: 13

Question: What is the solution?

Solve 401*l - 10 = 406*l for l.

Answer: -2

Question: What is the solution?

Solve -30*x = -22*x - 32 for x.

Answer: 4

Question: What is the solution?

Solve 0 = -428*u - 522 + 94 for u.

Answer:
-1