题目内容
分解因式:x2+3x-1=______.
令x2+3x-1=0,
则a=1,b=3,c=-1,
x=
=
=
,
x2+3x-1=(x-
)(x-
)=(x+
)(x+
).
故答案为:(x+
)(x+
).
则a=1,b=3,c=-1,
x=
-b±
| ||
| 2a |
-3±
| ||
| 2×1 |
-3±
| ||
| 2 |
x2+3x-1=(x-
-3+
| ||
| 2 |
-3-
| ||
| 2 |
3-
| ||
| 2 |
3+
| ||
| 2 |
故答案为:(x+
3-
| ||
| 2 |
3+
| ||
| 2 |
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