1) 6х²-5х-1=0
D=b²-4ac
D=25-4*6(-1)=1
x1=-b+√D/2a=5+1/12=1/2
x2=-b-√D/2a=5-1/12=1/3
2) x²-4x-21=0
D=4-4*1(-21)=88
x1=4+√88/2=4+2√22/2=2(2+√22)/2=2+√22
x2=4-√88/2=4-2√22/2=2(2-√22)/2=2-√22
1) 6х²-5х-1=0
D=b²-4ac
D=25-4*6(-1)=1
x1=-b+√D/2a=5+1/12=1/2
x2=-b-√D/2a=5-1/12=1/3
2) x²-4x-21=0
D=4-4*1(-21)=88
x1=4+√88/2=4+2√22/2=2(2+√22)/2=2+√22
x2=4-√88/2=4-2√22/2=2(2-√22)/2=2-√22