Write down the solution for this math problem: Solve 87*f + 34*f = 16*f - 1155 for f.
answer: -11

Write down the solution for this math problem: Solve -3152 = 191*c - 39 + 511 + 387 for c.
answer: -21

Write down the solution for this math problem: Solve -667*k - 12432 = -75*k for k.
answer: -21

Write down the solution for this math problem: Solve 2*l + 20*l = -5*l + 189 for l.
answer:
7