问题
解答题
先化简，再求值：(
|
答案
(
-x2 x-1
)÷2x 1-x x x-1
=（
+x2 x-1
）•2x x-1 x-1 x
=
•x2-2x x-1 x-1 x
=
•x(x-2) x-1 x-1 x
=x-2
当x=
-1时，原式=（3
-1）-2=3
-3．3
搜题请搜索小程序“爱下问搜题”
先化简，再求值：(
|
(
-x2 x-1
)÷2x 1-x x x-1
=（
+x2 x-1
）•2x x-1 x-1 x
=
•x2-2x x-1 x-1 x
=
•x(x-2) x-1 x-1 x
=x-2
当x=
-1时，原式=（3
-1）-2=3
-3．3
