> 数学 >
先化简,再求值(x-2y)(x方+2xy+4y方)-x(x-y)(x+y)+(2y)的三次方,x=5,y=-2
人气:151 ℃ 时间:2019-09-29 01:23:57
解答
(x-2y)(x方+2xy+4y方)-x(x-y)(x+y)+(2y)的三次方
=x³-(2y)³-x(x²-y²)+(2y)³
=x³-x³+xy²
=xy²
=5×(-2)²
=5×4
=20
推荐
猜你喜欢
© 2025 79432.Com All Rights Reserved.
电脑版|手机版