Write down the solution for this math problem: Solve -31*q + 15 = 8*q - 63 for q.
answer: 2

Write down the solution for this math problem: Solve 476*r - 19728 + 1554 = -223*r for r.
answer: 26

Write down the solution for this math problem: Solve 1229*a + 3171*a - 14599 = -3544*a - 221143 for a.
answer: -26

Write down the solution for this math problem: Solve -73*v + 50*v - 67*v = 2780 + 2890 for v.
answer:
-63