Question: What is the solution?

Solve 0 = -7*x + 14*x - 14 for x.

Answer: 2

Question: What is the solution?

Solve 9630*x = 9620*x - 80 for x.

Answer: -8

Question: What is the solution?

Solve 200 = -29*r + 4*r for r.

Answer: -8

Question: What is the solution?

Solve -13*o - 90 = -28*o for o.

Answer:
6