Question

solve t=9c-8d for d. assume all variables represent positive values.

Answer 1

t = 9c - 8d
t - 9c = -8d
(t - 9c)/-1 = -8d/-1
-(t - 9c) = 8d
-1(t - 9c)/8 = 8d/8
-1/8 • (t - 9c) = d or
-(t - 9c)/8 = d

Thus d = -(t - 9c)/8.