a). Δ=b²-4ac
Δ=(13)²-4x1x12=169-48=121
x1=[tex] \frac{-13- \sqrt{121} }{2*1} = \frac{-13-11}{2} = \frac{-24}{2} =-12[/tex]
x2=[tex] \frac{-13+11}{2*1} = \frac{2}{2} =1[/tex]
b). Δ=(-16)²-4*1*15=256-60=196
x1=[tex] \frac{16-14}{2} = \frac{2}{2} =1[/tex]
x2=[tex] \frac{16+14}{2} = \frac{30}{2} =15[/tex]
c).Δ=(-14)²-4*2*12=196-96=100
X1=[tex] \frac{14-10}{2*2} = \frac{4}{4} =1[/tex]
X2=[tex] \frac{14+10}{2*2} = \frac{24}{4} =6[/tex]
