Question: What is the solution?

Solve 66*c - 267*c = 1809 for c.

Answer: -9

Question: What is the solution?

Solve -3420 = 3358*m - 3073*m for m.

Answer: -12

Question: What is the solution?

Solve -40*r = -45*r + 25 for r.

Answer: 5

Question: What is the solution?

Solve -61*t = 6*t - t - 990 for t.

Answer:
15