> 数学 >
已知x+y=2,xy=-(1/2) 求x(x+y)²(1-y)-x(y+x)²的值
人气:402 ℃ 时间:2020-05-24 21:13:43
解答
x(x+y)²(1-y)-x(y+x)²
=x(x+y)²(1-y-1)
=-xy(x+y)²
=-(-1/2)×2²
=1/2×4
=2
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版