Question: What is the solution?

Solve 45*u = 217916 - 219626 for u.

Answer: -38

Question: What is the solution?

Solve -7*d + 9*d + 14 = 0 for d.

Answer: -7

Question: What is the solution?

Solve 100*o - 115 = 123*o for o.

Answer: -5

Question: What is the solution?

Solve -26*c + 82*c - 280 = 0 for c.

Answer:
5