D=4+60=64=8^(2),
x=(-2 ± 8)/2,
x_(1)=-5, x_(2)=3;
3x^(2)+30x-33=0,
D/4=225+99=324=18^(2),
x=(-15 ± 18)/3,
x_(1)=-11, x_(2)=1;
{(x+5)(x-3)>0,
{3(x+11)(x-1) ≥ 0;
{(x+5)(x-3)>0,
{(x+11)(x-1) ≥ 0;
{x<-5 или x>3,
{x ≤ -11 или x ≥ 1;
x ≤ -11 или x>3,
x ∈ (- ∞;-11] ∪ (3;+ ∞ ).