问题
解答题
先化简,再求值:(
|
答案
原式=
•a+2+a-2 (a+2)(a-2)
=(a-2)2 2a
•2a (a+2)(a-2)
=(a-2)2 2a
,a-2 a+2
当a=
-2时,原式=2
=
-2-22
+2-22
=1-2
-42 2
.2
先化简,再求值:(
|
原式=
•a+2+a-2 (a+2)(a-2)
=(a-2)2 2a
•2a (a+2)(a-2)
=(a-2)2 2a
,a-2 a+2
当a=
-2时,原式=2
=
-2-22
+2-22
=1-2
-42 2
.2