1 .196x^2-1=0
(14x+1)(14x-1)=0 x1=-1/14 x2=1/14
2.4x^2+12x+9=81
x^2+3x-18=0 (x+6)(x-3)=0 x1=-6 x2=3
3.x^2-7x-1=0
x=[7±根号（49+4）]/2 x1=(7+根号53）/2 x2=（7-根号53）/2
4.2x^2+3x=3
2x^2+3x-3=0 x=[-3±根号（9+24)]/4 x1=（-3+根号33）/4 x2=（-3-根号33）/4
5.x^2-2x+1=25
x^2-2x-24=0 (x-6)(x+4)=0 x1=6 x2=-4
6 .x(2x-5)=4x-10
2 x^2-9x+10=0 x=[9±根号（81-80）]/4 x=(9±1)/4 x1=5/2 x2=2
7.x^2+5x+7=3x+11
x^2+2x-4=0 (x+1)^2=5 x+1=±根号5 x1=-1+根号5 x2=-1-根号5
8.1-8x+16x^2=2-8x
16x^2-1=0 （4x+1)(4x-1)=0 x1=-1/4 x2=1/4