Question:
Solve -4 = -19*r + 21*r for r..

Answer:
-2

Question:
Solve 19649*u - 163444 - 154417 + 351 - 114768 = 0 for u..

Answer:
22

Question:
Solve 1870*p + 431262 = 7873*p + 1563*p for p..

Answer:
57

Question:
Solve -371*x + 379*x = 8 for x..

Answer:
1