这里a=1,b=3,c=1,
∵b2-4ac=9-4×1×1=5>0,
∴x=
−3±
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2 |
∴x1=
−3+
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2 |
−3−
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2 |
(2)分解因式得:(x-1)(x-9)=0,
可得x-1=0或x-9=0,
解得:x1=1 x2=9;
(3)开方得:2x-1=±(3x+2),
即2x-1=3x+2或2x-1=-(3x+2),
∴x1=-3,x2=-
1 |
5 |
(4)分解因式得:(x+2)(x-1-2)=0,
可得x+2=0或x-3=0,
解得:x1=-2,x2=3.
−3±
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2 |
−3+
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2 |
−3−
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2 |
1 |
5 |