X2-3x-18=0
X2 + 3x - 10 = 0
Factorizando
(x + 5)(x - 2) = 0
x + 5 = 0 x1 = - 5
x - 2 = 0 x2 = 2 S = {-5, 2}
X2 - 14x + 49 = 0
(x - 7)^2 0 cuadrado perfecto
x - 7 = 0 x1 = x2 = 7 S = {7}
X2 - 7X - 18 = 0
Factorizando
(x - 9)(x + 2)
x - 9 = 9 x1 = 9
x + 2 = 0 x2 = - 2 S = {- 2, 9}
x2 - 7x - 12 = 0
Por Báskara
delta = b^2 - 4.a.c = (-7)^2 - 4.1.(-12) = 49 + 48 = 97
x = [- b + ó - (raiz delta)]/2
x1 = [7 + (raiz 97)]/2
x2 = [7 - (raiz 97)]/2 S = {[7 - (raiz 97)]/2, [7 + (raiz 97)]/2}
