> 数学 >
先化简 再求值:[4(xy-1)^2-(xy+2)(2-xy)]1/4xy,其中x=-2,y=1/5
人气:403 ℃ 时间:2020-05-07 01:28:39
解答
[4(xy-1)^2-(xy+2)(2-xy)]1/4xy=[4(xy-1)^2 +(xy+2)(xy-2)]1/4xy=[4(xy)²-8(xy)+4+(xy)²-4]÷(4xy)=[5(xy)²-8(xy)]÷(4xy)=(5xy-8)/4已知x=-2,y=1/5,那么:xy=-2/5所以:原式=(5xy-8)/4=[5*(-2/5)-8]...
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版