题目内容
先化简,再请你用喜爱的数代入求值(
-
)÷
.
| 3x |
| x-1 |
| x |
| x+1 |
| x |
| x2-1 |
原式=
•
-
•
=3(x+1)-(x-1)
=3x+3-x+1
=2x+4,
把x=3代入上式:原式=2×3+4=10.
| 3x |
| x-1 |
| (x+1)(x-1) |
| x |
| x |
| x+1 |
| (x+1)(x-1) |
| x |
=3(x+1)-(x-1)
=3x+3-x+1
=2x+4,
把x=3代入上式:原式=2×3+4=10.
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