Respuesta :

X^2-14x-15=0
D=b^2-4ac=(-14)^2-4•1•(-15)=196+60=256
X1= -b + the root of D / 2a = 14 + 16 / 2 = 15
X2 = -b - the root of D / 2a = 14 - 16 / 2 = -1