Q: Solve:
Solve w - 392 = 71*w - 812 for w.

A: 6

Q: Solve:
Solve -130 + 30 = -5019*r + 5039*r for r.

A: -5

Q: Solve:
Solve -90*a - 2043 = -583*a + 6338 for a.

A:
17