Ta có :
\(x^3-xy^2+x^2y-y^3-1\)=\(\left(x^3+x^2y\right)-\left(xy^2+y^3\right)-1\)
=\(x^2\left(x+y\right)-y^2\left(x+y\right)-1=x^2.0-y^2.0-1=0-1=-1\)
tick mik nha !!
x3 - xy2 + x2y - y3 - 1
= x(x2 - y2) + y(x2 - y2) - 1
= x(x - y)(x + y) + y(x - y)(x + y) - 1
= (x+y)(x - y)(x + y) - 1
= (x + y)2(x - y) - 1
= 0 - 1
= - 1