问题
解答题
(1)先化简
(2)计算:
|
答案
(1)
÷(x-x2+2x 1+x
)=2 x+1
÷(x2+2x x+1
)=x2+x-2 x+1
•x(x+2) x+1
=x+1 (x-1)(x+2)
,x x-1
当x=2时,原式=
=2;2 2-1
(2)原式=
-1+2(1-1
-12
)=2 2
+1-1+2-2
=2.2
(1)先化简
(2)计算:
|
(1)
÷(x-x2+2x 1+x
)=2 x+1
÷(x2+2x x+1
)=x2+x-2 x+1
•x(x+2) x+1
=x+1 (x-1)(x+2)
,x x-1
当x=2时,原式=
=2;2 2-1
(2)原式=
-1+2(1-1
-12
)=2 2
+1-1+2-2
=2.2