Question: What is the solution?

Solve -211*r - 202*r = -383*r - 1290 for r.

Answer: 43

Question: What is the solution?

Solve -188*s + 908 - 4104 = 0 for s.

Answer: -17

Question: What is the solution?

Solve 1807 = 74*o - 213*o for o.

Answer: -13

Question: What is the solution?

Solve 437*o - 189*o + 1746*o + 116232 = -10*o for o.

Answer:
-58