Question: What is the solution?

Solve 74 = 30*s - 76 for s.

Answer: 5

Question: What is the solution?

Solve -30*x + 14*x = -11*x + 10 for x.

Answer: -2

Question: What is the solution?

Solve 129*a + 2190 + 1336 - 559 = 0 for a.

Answer: -23

Question: What is the solution?

Solve -1479*d + 822*d = 3123*d + 147420 for d.

Answer:
-39