Question: What is the solution?

Solve 81*r - 64*r + 8 = 25 for r.

Answer: 1

Question: What is the solution?

Solve 10*l - 1674 = -1604 for l.

Answer: 7

Question: What is the solution?

Solve -81*i - 505 = 1277 for i.

Answer: -22

Question: What is the solution?

Solve 0 = 39*k + 6*k - 270 for k.

Answer:
6