Question: What is the solution?

Solve -107*s - 3090 = 116*s + 67*s - 84*s for s.

Answer: -15

Question: What is the solution?

Solve 16 = 14*u - 10*u for u.

Answer: 4

Question: What is the solution?

Solve -154*u = -161*u + 7 for u.

Answer: 1

Question: What is the solution?

Solve 3509*k - 39287 = 8410 + 4938 for k.

Answer:
15