题目内容
计算及解方程:
(1)(2
-3
)×
(2)x2+4x+2=0;
(3)(x-3)(x+1)=2(x-3)
(1)(2
| 12 |
|
| 6 |
(2)x2+4x+2=0;
(3)(x-3)(x+1)=2(x-3)
(1)原式=2
-3
,
=12
-3
,
=9
;
(2)x2+4x+2=0,
∵a=1,b=4,c=2,
∴△=b2-4ac=16-4×1×2=8,
∴x=
=
=-2±
,
∴x1=-2+
,x2=-2-
;
(3)移项得:(x-3)(x+1)-2(x-3)=0,
分解因式得:(x-3)(x-1)=0,
则x-3=0,x-1=0,
解得:x1=3,x2=1.
| 72 |
| 2 |
=12
| 2 |
| 2 |
=9
| 2 |
(2)x2+4x+2=0,
∵a=1,b=4,c=2,
∴△=b2-4ac=16-4×1×2=8,
∴x=
-b±
| ||
| 2a |
-4±2
| ||
| 2 |
| 2 |
∴x1=-2+
| 2 |
| 2 |
(3)移项得:(x-3)(x+1)-2(x-3)=0,
分解因式得:(x-3)(x-1)=0,
则x-3=0,x-1=0,
解得:x1=3,x2=1.
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