d=4+12a^2=4(1+3a^2)
x1=(2+2корень(1+3а^2))/2a=(1+корень(1+3а^2))/a
x2=(2-2корень(1+3а^2)/2a=(1-корень(1+3а^2))/a
(1+корень(1+3а^2))/a+(2-2корень(1+3а^2))/a=1
(3-корень(1+3а^2))/a=1 a не=0
(3-корень(1+3а^2))=a
a^2+3a-4=0
a1=-4 a2=1
d=4+12a^2=4(1+3a^2)
x1=(2+2корень(1+3а^2))/2a=(1+корень(1+3а^2))/a
x2=(2-2корень(1+3а^2)/2a=(1-корень(1+3а^2))/a
(1+корень(1+3а^2))/a+(2-2корень(1+3а^2))/a=1
(3-корень(1+3а^2))/a=1 a не=0
(3-корень(1+3а^2))=a
a^2+3a-4=0
a1=-4 a2=1