Question: What is the solution?

Solve -15*d = -d - 38 - 18 for d.

Answer: 4

Question: What is the solution?

Solve -25*p + 15*p = -20 for p.

Answer: 2

Question: What is the solution?

Solve 482*d + 31 = -67*d + 580 for d.

Answer: 1

Question: What is the solution?

Solve -222 = 21*a - 621 for a.

Answer:
19