问题
解答题
计算: (1)
(2)(
(3)若x=
|
答案
(1)原式=2
-2-22
-2 24÷3
=2
-2-22
-22 2
=-2-2
;2
(2)原式=(
)2-22-(3-43
+4)2
=3-4-3+4
-42
=4
;2
(3)∵x=
+1,y=3
-1,3
∴x+y=2
,x-y=2,3
原式=(x+y)(x-y)
=2
×23
=4
.3
计算: (1)
(2)(
(3)若x=
|
(1)原式=2
-2-22
-2 24÷3
=2
-2-22
-22 2
=-2-2
;2
(2)原式=(
)2-22-(3-43
+4)2
=3-4-3+4
-42
=4
;2
(3)∵x=
+1,y=3
-1,3
∴x+y=2
,x-y=2,3
原式=(x+y)(x-y)
=2
×23
=4
.3