Question: What is the solution?

Solve 19*r - 69*r = -32*r - 198 for r.

Answer: 11

Question: What is the solution?

Solve 7617 = 5187*c - 169409 - 97885 for c.

Answer: 53

Question: What is the solution?

Solve -4*c = -24*c - 100 for c.

Answer: -5

Question: What is the solution?

Solve 0 = 31*h + 118*h - 4593 + 421 for h.

Answer:
28