(1).--2x(y-z)³+4x³(z-y)³=2x(z-y)³+4x³(z-y)³=2x(z-y)³(1+2x²)
(2).6y(x-y)²+2(y-x)³=6y(x-y)²-2(x-y)³=2(x-y)²[3y-(x-y)]=2(x-y)²(4y-x)
(1).--2x(y-z)³+4x³(z-y)³=2x(z-y)³+4x³(z-y)³=2x(z-y)³(1+2x²)
(2).6y(x-y)²+2(y-x)³=6y(x-y)²-2(x-y)³=2(x-y)²[3y-(x-y)]=2(x-y)²(4y-x)