题目内容
解方程:
(1)x2-7x-1=0;
(2)x(2x-5)=4x-10
(1)x2-7x-1=0;
(2)x(2x-5)=4x-10
(1)a=1,b=-7,c=-1;
b2-4ac=53;
x=
;
x1=
,x2=
;
(2)原方程可化为:x(2x-5)-2(2x-5)=0;
(2x-5)(x-2)=0,
x-2=0或2x-5=0;
解得:x1=2,x2=
.
b2-4ac=53;
x=
7±
| ||
| 2 |
x1=
7+
| ||
| 2 |
7-
| ||
| 2 |
(2)原方程可化为:x(2x-5)-2(2x-5)=0;
(2x-5)(x-2)=0,
x-2=0或2x-5=0;
解得:x1=2,x2=
| 5 |
| 2 |
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