Question: What is the solution?

Solve 25*d = -26*d - 9*d - 600 for d.

Answer: -10

Question: What is the solution?

Solve 431*h = 325*h - 212 for h.

Answer: -2

Question: What is the solution?

Solve 9811146 - 9808338 = -35*s - 4*s for s.

Answer: -72

Question: What is the solution?

Solve -146*r - 21840 = -89*r + 154*r + 101*r for r.

Answer:
-70