解①原式={(2y-z)×[2y(z+2y)+z²]}²={(2y-z)[(2y)²+2yz+z²]}²=[(2y)³-z³]²=(8y³-z³)²=64y^6-16y³z³+z^6 解②原式=(x+y)²(x²-xy+y²...