题目内容
计算
(1)(3
+
-4
)÷
(2)先化简,再求值:
-
,且a=
.
(1)(3
| 18 |
| 1 |
| 5 |
| 50 |
|
| 32 |
(2)先化简,再求值:
| 1-2a+a2 |
| a-1 |
| ||
| a2-a |
| 1 | ||
2+
|
(1)原式=(9
+
-2
)÷(4
)
=8
÷4
=2;
(2)原式=
-
=a-1+
当a=
时,
原式=
-1+2+
=2-
-1+2+
=3.
| 2 |
| 2 |
| 2 |
| 2 |
=8
| 2 |
| 2 |
=2;
(2)原式=
| (a-1)2 |
| a-1 |
| ||
| a(a-1) |
=a-1+
| 1 |
| a |
当a=
| 1 | ||
2+
|
原式=
| 1 | ||
2+
|
| 3 |
=2-
| 3 |
| 3 |
=3.
练习册系列答案
相关题目