解方程:(1)3x2+8x-3=0(配方法)(2)(2x-3)(x-4)=9(3)(y-2)2=(2y+3)2(4)3(x-1)2-5(x-

2025-05-01 15:26:17
推荐回答(1个)
回答1:

(1)∵x2+

8
3
x=1,
x2+
8
3
x+(
4
3
2=1+(
4
3
2
(x+
4
3
2=
25
9

∴x+
4
3
5
3

∴x1=
1
3
,x2=-3;
(2)2x2-11x+3=0,
∵△=121-4×2×3=97,
∴x=
11±
97
2×2

∴x1=
11+
97
4
,x2=
11?
97
4

(3)∵y-2=±(2y+3),
∴y-2=2y+3或y-2=-2y-3,
∴y1=-5,x2=-
1
3

(4)∵[3(x-1)+1][(x-1)-2]=0,
∴3(x-1)+1=0或(x-1)-2=0,
∴x1=
2
3
,x2=3.