问题
解答题
已知a=
(1)a2-b2; (2)
|
答案
(1)原式=(a+b)(a-b)
=(
+3
+2
-3
)(2
+3
-2
+3
)2
=2
×23 2
=4
;6
(2)原式=b-a ab
=
-3
-2
-3 2 (
+3
)(2
-3
)2
=-2
.2
已知a=
(1)a2-b2; (2)
|
(1)原式=(a+b)(a-b)
=(
+3
+2
-3
)(2
+3
-2
+3
)2
=2
×23 2
=4
;6
(2)原式=b-a ab
=
-3
-2
-3 2 (
+3
)(2
-3
)2
=-2
.2