Question:
Solve -15*r + 27 = -18*r for r..

Answer:
-9

Question:
Solve -947*z + 978*z - 62 = 0 for z..

Answer:
2

Question:
Solve -115*u = 283 + 407 for u..

Answer:
-6

Question:
Solve -1142*y + 1244*y + 1938 = 0 for y..

Answer:
-19