题目内容
计算:
(1)(
+
)÷
;
(2)已知x=2+
,y=2-
,求x2-y2的值.
(1)(
| 48 |
| 1 |
| 4 |
| 6 |
| 27 |
(2)已知x=2+
| 5 |
| 5 |
(1)(
+
)÷
,
=
+
,
=
+
,
=
+
;
(2)x2-y2,
=(x+y)(x-y),
=(2+
+2-
)(2+
-2+
),
=8
.
| 48 |
| 1 |
| 4 |
| 6 |
| 27 |
=
|
| 1 |
| 4 |
|
=
|
| 1 |
| 4 |
|
=
| 4 |
| 3 |
| 1 |
| 12 |
| 2 |
(2)x2-y2,
=(x+y)(x-y),
=(2+
| 5 |
| 5 |
| 5 |
| 5 |
=8
| 5 |
练习册系列答案
相关题目