Question

Calculati delta:
a= -1
b= 8
c=0

Answer 1

Δ=b²-4*a*c
Δ=8²-4*(-1)*0=64

Answer 2

Ecuatia are forma : - x² + 8x = 0  => Δ=8² -4*(/1)*0 = 64 ;

$x_{1;2}=\frac{-b\pm\sqrt\Delta}{2a}=\frac{-8\pm8}{-2}\Rightarrow\;x_1=0\;si\;x_2=+8$