Question: What is the solution?

Solve 19354 = -28*r + 19298 for r.

Answer: -2

Question: What is the solution?

Solve -2830*u + 1413*u = -1416*u - 12 for u.

Answer: 12

Question: What is the solution?

Solve -1397 = 92*r - 306 + 657 for r.

Answer: -19

Question: What is the solution?

Solve -586*z - 11893 = 2674 - 2261 for z.

Answer:
-21