(x+y+z)^2=
5(a-1)^2-10(1-a)=
ab(x-y)^2-ab^2(y-x)^2=
x(x-y)-y(y-x)^2=
2mn-m^2-n^2=
(a-b)^2-4(b-a)+4=
202^2+202*196+98^2=
(x+y+z)^2=
5(a-1)^2-10(1-a)=
ab(x-y)^2-ab^2(y-x)^2=
x(x-y)-y(y-x)^2=
2mn-m^2-n^2=
(a-b)^2-4(b-a)+4=
202^2+202*196+98^2=
x^2+y^2+z^2+2xy+2xz+yz
(a-1)(5a+5)
(x-y)^2[ab(1-b)]
(x-y)(x-xy+y^2)
-(m-n)^2
(a-b+2)^2
(202+98)^2