0.3x^2=0.027 x^2=0.027/0.3 x^2=0.09 x1=+0.09 x2=-0.09
0.5x^2=30 x^2=30/0.5 x^2=60 x1=+60 x2= -60
-5x^2=1/20 x^2=1/20/(-5) x^2=-0.01 Нет корней
x^3-3x=0 x1=0 , потом делим на x, x^2-3=0 x^2=3 x2=3^0.5 x3=-(3^0.5)
x^3-11x=0 x1=0 ,потом делим на x, x^2-11=0 x^2=11 x2=11^0.5 x3=-(11^0.5)