QUESTION: Math problem: Solve 20*z - 4 = 21*z for z.
ANS: -4
QUESTION: Math problem: Solve -13*v + 522 = -580 + 1232 for v.
ANS: -10
QUESTION: Math problem: Solve 146*r = 422*r - 134*r - 98*r - 176 for r.
ANS: 4
QUESTION: Math problem: Solve -200 = -69*v - 717 - 656 for v.
ANS:
-17