Question: What is the solution?

Solve 21*x = 8*x for x.

Answer: 0

Question: What is the solution?

Solve 3*v + 8 = v for v.

Answer: -4

Question: What is the solution?

Solve -51*y - 15159 = 467*y - 29*y for y.

Answer: -31

Question: What is the solution?

Solve 0 = 98*u + 40*u - 486446 + 481202 for u.

Answer:
38