Question:
Solve -520*r + 2455 = -1615 - 4446 + 196 for r..

Answer:
16

Question:
Solve 166*d - 47*d - 2734 + 592 = 0 for d..

Answer:
18

Question:
Solve -472*h = 691*h + 77*h + 148800 for h..

Answer:
-120

Question:
Solve 38*k = -30*k - 160 - 656 for k..

Answer:
-12