Question: What is the solution?

Solve 406*f + 90 = 415*f for f.

Answer: 10

Question: What is the solution?

Solve -33 = 5*z - 28 for z.

Answer: -1

Question: What is the solution?

Solve 81*y = 74*y for y.

Answer: 0

Question: What is the solution?

Solve -110*a = -136*a + 78 for a.

Answer:
3