Write down the solution for this math problem: Solve 40 = 30*a - 80 for a.
answer: 4

Write down the solution for this math problem: Solve -122*b - 8 = -120*b for b.
answer: -4

Write down the solution for this math problem: Solve 1715*u + 2647*u - 37046 - 103029 = 43129 for u.
answer: 42

Write down the solution for this math problem: Solve -49*f - 290 = 70*f - 5764 for f.
answer:
46