P=x2(y-z) + y2z - y2x + z2x-z2y
=x2(y-z) + yz(y-z) - x(y-z)(y+z)
=(y-z)(x2+yz-xy-xz)
=(y-z)[x(x-z)-y(x-z)]
= (x-y)(y-z)(x-z)
P=x2(y-z)+y2(z-x)+z2(x-y)
=x2(y-z)-y2[(y-z)+(x-y)]+z2(x-y)
=(y-z)(x2-y2)-(x-y)(y2-y2)
=(y-z)(x+y)(x-y)-(x-y)(y+z)(y-z)
=(y-z)(x-y)(x-z)
Ta có :
\(P=x^2\left(y-z\right)+y^2\left(z-x\right)+z^2\left(x-y\right)\)
\(P=x^2\left(y-z\right)+y^2z-xy^2+xz^2-yz^2\)
\(P=x^2\left(y-z\right)+\left(y^2z-yz^2\right)-\left(xy^2-xz^2\right)\)
\(P=x^2\left(y-z\right)\).............
