1) х5+х3-6х=0 2) х3-3х2-4х+12=0 3)1) х4-6х2+8=0

1) х5+х3-6х=0 x(x4+x2-6)=0 x=0 x2(x2+1)=6 x=sqrt{6} x2+1=6 x2=5 x=sqrt{5}