Q: What is the solution?
Solve 112*d - 63*d + 1391 - 19 = 0 for d.

A: -28

Q: What is the solution?
Solve 0 = -6*o - 4*o + 30 for o.

A: 3

Q: What is the solution?
Solve 2979 + 1351 = 498*b - 152 for b.

A:
9