Question: What is the solution?

Solve 0 = -193*x + 189*x + 12 for x.

Answer: 3

Question: What is the solution?

Solve 10314 + 8393 = 884*k - 2509 for k.

Answer: 24

Question: What is the solution?

Solve 0 = 25*r + 174 - 49 for r.

Answer: -5

Question: What is the solution?

Solve -15*q = 81*q for q.

Answer:
0