Question: What is the solution?

Solve -105 = 10*x - 31*x for x.

Answer: 5

Question: What is the solution?

Solve -124082 = -97*r - 120687 for r.

Answer: 35

Question: What is the solution?

Solve 0 = 139*c - 129*c + 30 for c.

Answer: -3

Question: What is the solution?

Solve 0 = 34*a - 672 + 468 for a.

Answer:
6