[tex]y(a-b)=c(y+a)\ \ \ \ |\text{use distributive property}\\\\ya-yb=cy+ca\ \ \ \ |-cy\\\\ya-yb-yc=ca\\\\y(a-b-c)=ca\ \ \ \ |:(a-b-c)\neq0\\\\\boxed{y=\dfrac{ca}{a-b-c}}[/tex]
