Question: What is the solution?

Solve -78*u = -83*u - 15 for u.

Answer: -3

Question: What is the solution?

Solve 34*m + 246 = -20*m - 402 for m.

Answer: -12

Question: What is the solution?

Solve -84 = 18*t + 28*t - 58*t for t.

Answer: 7

Question: What is the solution?

Solve 8*k = -9*k - 15*k + 19*k - 637 for k.

Answer:
-49