题目内容
先化简,再求值:
÷(m-
),其中m是方程2x2-2x-1=0的解.
| 2m-6 |
| m2-4 |
| 4m-9 |
| m-2 |
原式=
÷
=
÷
=
•
=
,
∵m是方程2x2-2x-1=0的解,
∴2m2-2m-1=0,即m2-m=
,
∴原式=
=-
.
| 2(m-3) |
| (m+2)(m-2) |
| m(m-2)-4m+9 |
| m-2 |
=
| 2(m-3) |
| (m+2)(m-2) |
| (m-3)2 |
| m-2 |
=
| 2(m-3) |
| (m+2)(m-2) |
| m-2 |
| (m-3)2 |
=
| 2 |
| m2-m-6 |
∵m是方程2x2-2x-1=0的解,
∴2m2-2m-1=0,即m2-m=
| 1 |
| 2 |
∴原式=
| 2 | ||
|
| 4 |
| 11 |
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