Question:
Solve 429*k + 1000*k - 280*k = -20*k + 105210 for k..

Answer:
90

Question:
Solve -38*s = -52*s - 98 for s..

Answer:
-7

Question:
Solve 2*v - 8*v = 12 for v..

Answer:
-2

Question:
Solve 0 = 5*w - 3*w for w..

Answer:
0