0,2x^2+4=0 1/3x^2+1/9=0 (2x-1)^2=1-4x 3-(4x+1)(3-x)=x^2 !

-0,2 х^2+4=0
-0,2х^2= - 4
х^2=20
х= ±2\|5

1/3 х^2 +1/9=0
1/3 х^2 = - 1/9
х^2 = - 1/3 - корней нет

(2х -1)^2=1-4х
4х^2 -4х+1 - 1+4х=0
4х^2 =0
х^2=0

3- (4х+1)(3- х)=х^2
3-12х+4х^2 - 3+х - х^2=0
3х^2 -11х=0
х(3х -11)=0
х1=0
3х -11=0
3х=11
х2=3 2/3