Write down the solution for this math problem: Solve -234 = -266*r + 233*r + 459 for r.
answer: 21

Write down the solution for this math problem: Solve -195*b - 4780 + 5772 = -8173 for b.
answer: 47

Write down the solution for this math problem: Solve 8*n - 2569 = 51*n + 203 + 238 for n.
answer: -70

Write down the solution for this math problem: Solve 169*v = -172*v - 220*v + 638*v - 5698 for v.
answer:
74