Q: Solve:
Solve 13*f + 2040 - 2157 = 0 for f.

A: 9

Q: Solve:
Solve -6898106*r - 1372 = -6898155*r for r.

A: 28

Q: Solve:
Solve -6111 = 155*q + 177*q - 41*q for q.

A:
-21