y(x-1)=z
Simplify by opening the brackets:
yx-1y=z
yx-y=z
Get rid of the "y" variable on the left side by adding "y" to both sides:
yx-y+y=z+y
yx=z+y
Get rid of another "y" variable on the left side by diving each side by "y":
(yx)÷y=(z+y)÷y
Solution:
x=(z+y)÷y
Hope this helps :)