解方程：
(1)x^2-7x-1=0
(x-3.5)^2=13.25
x-3.5=±√13.25
x1=3.5+√13.25
x2=3.5-√13.25 .
(2)2x^2+3x=3
x^2+1.5x-1.5=0
Δ=1.5^2+4*1.5=8.25
x1=(-1.5+√8.25)/2
x2=(-1.5-√8.25)/2
(3)x^2-2x+1=25
(x-1)^2=25
x-1=±5
x1=6 x2=-4
(4) x(2x-5)=4x-10
2x^2-5x=4x-10
2 x^2-9x+10=0
(2x-5)(x-2)=0
x1=5/2 x2=2
(5) x^2+5x+7=3x+11
x^2+2x-4=0
(x+1)^2=5
x+1=±√5
x1=√5-1
x2=-√5-1 .
(6)1-8x+16x^2=2-8x
16x^2=1
x^2=1/16
x=±1/4
x1=1/4 x2=-1/4