Question:
Solve 87 = 10*u + 97 for u..

Answer:
-1

Question:
Solve -1029*q - 13518 + 1227 = -2001 for q..

Answer:
-10

Question:
Solve -6306 = -204*a - 22830 for a..

Answer:
-81

Question:
Solve 893 = 49*k - 332 for k..

Answer:
25