问题
解答题
化简求值：(1+
|
答案
原式=(
+x2-y2 x2-y2
)•y2 x2-y2 x-y x
=
•x2 x2-y2 x-y x
=
•x2 (x+y)(x-y) x-y x
=
．x x+y
由x-3y=0，得x=3y，
∴原式=
=3y 3y+y
=3y 4y
．3 4
搜题请搜索小程序“爱下问搜题”
化简求值：(1+
|
原式=(
+x2-y2 x2-y2
)•y2 x2-y2 x-y x
=
•x2 x2-y2 x-y x
=
•x2 (x+y)(x-y) x-y x
=
．x x+y
由x-3y=0，得x=3y，
∴原式=
=3y 3y+y
=3y 4y
．3 4