问题 解答题
(1)x2+2=3x;
(2)(x-1)(x+2)=70;
(3)(y+3)2-2=0;
(4)(3x-2)2=2(2-x);
(5)(x+7)(x-7)=2x-50;
(6)(3-2
2
)x2+2(
2
-1)x-1=0
答案

(1)移项,得x2+2-3x=0,

即(x-1)(x-2)=0

∴x-1=0或x-2=0

解得x1=1,x2=2.

(2)整理(x-1)(x+2)=70,得

x2+x-72=0,即(x-8)(x+9)=0

∴x-8=0或x+9=0

解得x1=-9,x2=8.

(3)移项,得(y+3)2=2,

∴y+3=±

2

解得y=-3±

2

(4)整理(3x-2)2=2(2-x),得

9x2-10x=0,即x(9x-10)=0

∴x1=0,x2=

10
9

(5)整理(x+7)(x-7)=2x-50,得

x2-2x+1=0,即(x-1)2=0

∴x-1=0

∴x1=x2=1.

(6)由(3-2

2
)x2+2(
2
-1)x-1=0,得

[(3-2

2
)x+1](x-1)=0

∴(3-2

2
)x+1=0或x-1=0

解得x1=1,x2=-3-2

2

单项选择题
单项选择题 A1型题