Question: What is the solution?

Solve -u + 10 = 13 for u.

Answer: -3

Question: What is the solution?

Solve 503*s + 14400 = -81*s + 8*s for s.

Answer: -25

Question: What is the solution?

Solve 0 = -9*o + 27 for o.

Answer: 3

Question: What is the solution?

Solve -128166*q - 2921 = -128056*q + 1699 for q.

Answer:
-42