Question:
Solve -9*k - 15 = 39 for k..

Answer:
-6

Question:
Solve -534*c + 20903 = -3488*c - 462*c - 74745 for c..

Answer:
-28

Question:
Solve 80 = 32*s - 16*s for s..

Answer:
5

Question:
Solve -71*s - 897*s - 13133 - 12194 = -151*s for s..

Answer:
-31