Q: What is the solution?
Solve 19*d + 135*d + 45*d = 1990 for d.

A: 10

Q: What is the solution?
Solve 8*z - 2 = 10*z for z.

A: -1

Q: What is the solution?
Solve -1945*r + 22212 = -4413*r for r.

A:
-9