Write down the solution for this math problem: Solve -8*r = -7*r for r.
answer: 0

Write down the solution for this math problem: Solve -143 - 85 = 22*o - 162 for o.
answer: -3

Write down the solution for this math problem: Solve 125*r = 121*r for r.
answer: 0

Write down the solution for this math problem: Solve g = 3*g - 3*g for g.
answer:
0