问题
解答题
先化简,再求值:
|
答案
原式=
•x(x-2) (x+2)(x-2)
+x+2x+2 2x
=
+x+21 2
=x+
,5 2
当x=1-sin30°=1-
=1 2
,原式=1 2
+1 2
=3.5 2
先化简,再求值:
|
原式=
•x(x-2) (x+2)(x-2)
+x+2x+2 2x
=
+x+21 2
=x+
,5 2
当x=1-sin30°=1-
=1 2
,原式=1 2
+1 2
=3.5 2