QUESTION: Math problem: Solve 0 = 21*z - 20 + 251 for z.
ANS: -11
QUESTION: Math problem: Solve 45293 = -1162*v - 1187 for v.
ANS: -40
QUESTION: Math problem: Solve -294 = 32*d + 17*d for d.
ANS: -6
QUESTION: Math problem: Solve -350*r + 162*r = -154*r - 850 for r.
ANS:
25