1.4X^2-256=0
4x^2=256
x^2=64
x1=8,x2=-8
2.4(x-1/2)^2=1
(x-1/2)^2=1/4
x-1/2=1/2,x-1/2=-1/2
x1=1/2+1/2=1
x2=-1/2+1/2=0
3.-x^2+2x+3=0
x^2-2x-3=0
(x-3)*(x+1)=0
x1=3,x2=-1
4.3x^2+8x-3=0
(3x-1)*(x+3)=0
x1=1/3
x2=-3