Q: Solve 0 = 12*x - 28*x - 23*x + 507 for x.

A: 13

Q: Solve 189*y - 4932 = 549 for y.

A: 29

Q: Solve 17*y - 11*y + 48 = 0 for y.

A: -8

Q: Solve 39*n + 28*n = -14*n + 405 for n.

A:
5