QUESTION: Math problem: Solve 0 = 98*j - 87*j + 143 for j.
ANS: -13
QUESTION: Math problem: Solve -5*s = -0*s - 5 for s.
ANS: 1
QUESTION: Math problem: Solve -135*r + 128*r - 21 = 0 for r.
ANS: -3
QUESTION: Math problem: Solve 52 = -6*k + 22 for k.
ANS:
-5