Q: Solve:
Solve 20199 - 2780 = -478*a - 267 for a.

A: -37

Q: Solve:
Solve 0 = 16*i + 11457363 - 11457843 for i.

A: 30

Q: Solve:
Solve -19689 = -345*u - 57*u + 4431 for u.

A:
60