Question: What is the solution?

Solve -2730 = -9808*o + 9938*o for o.

Answer: -21

Question: What is the solution?

Solve 8*y - 133 = -73*y - 52*y for y.

Answer: 1

Question: What is the solution?

Solve r = -228*r - 114*r - 5831 for r.

Answer: -17

Question: What is the solution?

Solve -69*r + 493 - 647 = 743 for r.

Answer:
-13