Question: What is the solution?

Solve -209 = -99*j - 21*j + 151 for j.

Answer: 3

Question: What is the solution?

Solve -j - 4 = j for j.

Answer: -2

Question: What is the solution?

Solve 1004*r - 329*r = 12150 for r.

Answer: 18

Question: What is the solution?

Solve 36*r + 5897 - 5609 = 0 for r.

Answer:
-8