Răspuns:
1. a) Δ= [tex]b^{2}[/tex]-4ac= 64 - 4*1*6= 64-24= 40
x1=(-b-[tex]\sqrt{D}[/tex])/2a = (8-2[tex]\sqrt{10}[/tex])/2 =4-[tex]\sqrt{10}[/tex]
x2=8+2[tex]\sqrt{10}[/tex]/2= 4+[tex]\sqrt{10}[/tex]
b) S= x1+x2= 4-[tex]\sqrt{10}[/tex] +4 -[tex]\sqrt{10}[/tex] = 8
P=x1*x2= (4-[tex]\sqrt{10}[/tex] )*(4+[tex]\sqrt{10}[/tex] )= 16-4[tex]\sqrt{10}[/tex] + 4[tex]\sqrt{10}[/tex] -10= 16-10= 6
P=6 S= 8
3) Δ=[tex]b^{2}[/tex]-4ac= 25-4*1*6= 25-24=1
x1= (-b-[tex]\sqrt{D}[/tex])/2a= 5-1/2= 4/2= 2
x2= 5+1/2= 6/2= 3
