Answer: x = z/(1-y)
Work Shown:
x - xy = z
x*1 - x*y = z
x*(1 - y) = z .... distributive rule in reverse
x = z/(1-y) ..... divide both sides by (1-y)
The distributive rule is a*(b+c) = a*b+a*c. You can also say a*(b-c) = a*b-a*c. In this case, we factored out the common factor x.