Write down the solution for this math problem: Solve -77 = 10*j - 21*j for j.
answer: 7

Write down the solution for this math problem: Solve 28*a = 17*a - 99 for a.
answer: -9

Write down the solution for this math problem: Solve -191*w + 22651 = 75*w + 4297 for w.
answer: 69

Write down the solution for this math problem: Solve -490 - 420 + 244 = 74*c for c.
answer:
-9