作业帮已知y-2x=0,求代数式（x^+xy+y^）（x^—y^)/(x^-y^)(x^-xy+y^) 对....
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/29 17:49:13
x){}K+u*l
tmlz{"NR2N0QÔ8M}8]
Қ
O"}1 j~
rь=5ٌ
8Mj6j5b1H3,
%@ # L[
0 }f@fS!Hؤ(22́on_\g
P0e';;^.Ɏ';Ny6}ήg}Ov4<ٱ
)L!1e }Og/xc
已知y-2x=0,求代数式（x^+xy+y^）（x^—y^)/(x^-y^)(x^-xy+y^) 对....
已知y-2x=0,求代数式（x^+xy+y^）（x^—y^)/(x^-y^)(x^-xy+y^)
对....
已知y-2x=0,求代数式（x^+xy+y^）（x^—y^)/(x^-y^)(x^-xy+y^) 对....
题目应是 已知y-2x=0,求代数式(x^2+y^2)(x^2-xy+y^2)\(x^2+xy+y^2)(x^2-y^2)
y-2x=0
y=2x
(x^2-y^2)(x^2-xy+y^2)/(x^2+xy+y^2)(x^2-y^2).
=(x^2-xy+y^2)/(x^2+xy+y^2)
=(x^2-2x^2+4x^2)/(x^2+2x^2+4x^2)
=3x^2/7x^2
=3/7
那么首先上下同时削掉一个（x^—y^)
然后因为y-2x=0，所以y=2x
带入即可