Respuesta :
x^2 - 8x - 9 = 0
x^2 - 8x = 9
(x - 4)^2 - 16 = 9
(x - 4)^2 = 25
x - 4 = +/- sqrt25 = +/- 5
x = 5 + 4, -5 + 4
Solution set is {-1, 9}
x^2 - 8x = 9
(x - 4)^2 - 16 = 9
(x - 4)^2 = 25
x - 4 = +/- sqrt25 = +/- 5
x = 5 + 4, -5 + 4
Solution set is {-1, 9}