Question: What is the solution?

Solve 6*k - 9*k + 12 = 0 for k.

Answer: 4

Question: What is the solution?

Solve 0 = -2023*f + 2013*f - 60 for f.

Answer: -6

Question: What is the solution?

Solve 25*o - 27*o = -4 for o.

Answer: 2

Question: What is the solution?

Solve 40 = 52*r - 57*r for r.

Answer:
-8