Q: Solve 7*x + 21 + 0 = 0 for x.

A: -3

Q: Solve -350*q + 24 = -356*q for q.

A: -4

Q: Solve -558 = 122*z - 70 for z.

A: -4

Q: Solve 24*l = 1935 - 2391 for l.

A:
-19