Question: What is the solution?

Solve 13*l + 215 - 189 = 0 for l.

Answer: -2

Question: What is the solution?

Solve 21*j = 17*j - 24 for j.

Answer: -6

Question: What is the solution?

Solve 6820 = -841*j + 549*j - 2103*j - 165620 for j.

Answer: -72

Question: What is the solution?

Solve -4*d + 8*d + 12 = 0 for d.

Answer:
-3