Question: What is the solution?

Solve 60*o + 91*o = -248*o - 399 for o.

Answer: -1

Question: What is the solution?

Solve 15947*x = 9031*x - 214396 for x.

Answer: -31

Question: What is the solution?

Solve 65*r - 280 = 135*r for r.

Answer: -4

Question: What is the solution?

Solve -324*l + 4356 = 100*l - 908*l for l.

Answer:
-9