选用适当的方法解下列方程:(1)(x-2) 2 -9=0;(2)x 2 +2x=3;(3) x 2 -2 3 x+3=

2025-04-07 23:16:55
推荐回答(1个)
回答1:

(1)∵(x-2-3)(x-2+3)=0,
∴x-2-3=0或x-2+3=0,
∴x 1 =5,x 2 =-1;
(2)∵x 2 +2x-3=0,
∴(x+3)(x-1)=0,
∴x+3=0或x-1=0,
∴x 1 =-3,x 2 =1;
(3)∵x 2 -2
3
x+(
3
2 =0,
∴(x-
3
2 =0,
∴,x 1 =x 2 =
3

(4)∵a=2,b=-5,c=1,
∴△=(-5) 2 -4×2×1=17,
∴x=
17
2×2

∴x 1 =
5+
17
4
,x 2 =
5-
17
4