题目内容
已知2x-3=0,求代数式| x(4x-3) |
| x2-9 |
| 6 |
| x2-9 |
| 2 |
| x-3 |
分析:首先利用分式的混合运算的法则化简,然后代入数值计算即可求解.
解答:解:
+
÷
=
+
•
=
+
=
=
,
∵2x-3=0,
∴原式=0.
| x(4x-3) |
| x2-9 |
| 6 |
| x2-9 |
| 2 |
| x-3 |
=
| 4x2-3x |
| x2-9 |
| 6 |
| x2-9 |
| x-3 |
| 2 |
=
| 4x2-3x |
| x2-9 |
| 3 |
| x+3 |
=
| 4x2-9 |
| x2-9 |
=
| (2x+3)(2x-3) |
| x2-9 |
∵2x-3=0,
∴原式=0.
点评:此题主要考查了分式的化简求值,解答此题的关键是把分式化到最简,然后代值计算.
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