(5-x)^2=
36-y^2=
(3x+8y)^2=
(2+y)^3=
(3+2x)^2=
2*(x-y)+6*(x+y)=
3*(x+y)-2*(x-4y)=
(2a-0,3b)*(3a+5b)=
(x-3)*(x^2-2x+3)=
(x-2)*(4-x)=

0