问题
解答题
解方程:(1) x2+4x-4=0
(2)5(x-2)2=3(2-x)
答案
(1)x2+4x=4
x2+4x+4=8
(x+2)2=8
x+2=±22
x=-2±22
∴x1=-2+2
,x2=-2-22
.2
(2)5(x-2)2-3(2-x)=0
(x-2)(5x-10+3)=0
(x-2)(5x-7)=0
∴x1=2,x2=
.7 5
解方程:(1) x2+4x-4=0
(2)5(x-2)2=3(2-x)
(1)x2+4x=4
x2+4x+4=8
(x+2)2=8
x+2=±22
x=-2±22
∴x1=-2+2
,x2=-2-22
.2
(2)5(x-2)2-3(2-x)=0
(x-2)(5x-10+3)=0
(x-2)(5x-7)=0
∴x1=2,x2=
.7 5