# How do you solve using the quadratic formula x^2-5x-14=0?

May 16, 2015

$y = {x}^{2} - 5 x - 14 = 0$

D = d^2 = 25 + 56 = 81 -> d = +-9

x = 5/2 + 9/2 = 14/2 = 7

x = 5/2 - 9/2 = -4/2 = -2

There is another way that is faster. (new AC Method)
Find 2 numbers knowing product (-14) and sum (7). Compose factor pairs of (-14): (-1, 14)(-2, 7). This last sum is 5 = -b. Then the 2 real roots are: -2 and 7