Question: What is the solution?

Solve -13*q + 20 = 7*q for q.

Answer: 1

Question: What is the solution?

Solve 68 = 3*i + 65 for i.

Answer: 1

Question: What is the solution?

Solve 30*i = 40*i - 20 for i.

Answer: 2

Question: What is the solution?

Solve -88*c = -39*c + 490 for c.

Answer:
-10