Q: Solve:
Solve -911*u - 7453 = 6262 + 5416 for u.

A: -21

Q: Solve:
Solve 21*v - 30*v = 63*v - 648 for v.

A: 9

Q: Solve:
Solve -514*r - 336 - 1167 = 39 for r.

A:
-3