Question: What is the solution?

Solve -31*a = -36*a + 15 for a.

Answer: 3

Question: What is the solution?

Solve -8386*a + 2594*a - 434800 + 35213 = 249117 for a.

Answer: -112

Question: What is the solution?

Solve 402*y - 108 = 438*y for y.

Answer: -3

Question: What is the solution?

Solve -486*y = 142*y - 12*y - 22176 for y.

Answer:
36