Question:
Solve -42*r - 144*r = -5961 - 12777 + 4602 for r..

Answer:
76

Question:
Solve 198*d - 12710 = 1747*d + 26563 - 8293 for d..

Answer:
-20

Question:
Solve -860*u + 866*u + 36 = 0 for u..

Answer:
-6

Question:
Solve -54*u + 20 = -58*u for u..

Answer:
-5