Question: What is the solution?

Solve 661*z = 657*z + 60 for z.

Answer: 15

Question: What is the solution?

Solve 3*x + 3784 - 7628 + 3700 = 0 for x.

Answer: 48

Question: What is the solution?

Solve -14*x = 80 + 4 for x.

Answer: -6

Question: What is the solution?

Solve -28 = 7*k - 11*k for k.

Answer:
7