How do you solve using the quadratic formula $x^{2} - 7 x - 8 = 0$ $x^2-7x-8=0$ ?

Question

3308 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-11-13T22:35:12

$x = 8$ $x = 8$ and $x = - 1$ $x = -1$

This quadratic can be factored to:

$(x - 8) (x + 1) = 0$ $(x - 8)(x + 1) = 0$

Solving for $(x - 8)$ $(x - 8)$ gives:

$\frac{(x - 8) (x + 1)}{(x + 1)} = \frac{0}{x + 1}$ $((x - 8)(x + 1))/((x + 1)) = 0/(x + 1)$

$x - 8 = 0$ $x - 8 = 0$

$x - 8 + 8 = 0 + 8$ $x - 8 + 8 = 0 + 8$

$x = 8$ $x = 8$

Solving for $(x + 1)$ $(x + 1)$ gives:

$\frac{(x - 8) (x + 1)}{(x - 8)} = \frac{0}{x - 8}$ $((x - 8)(x + 1))/((x - 8)) = 0/(x - 8)$

$x + 1 = 0$ $x + 1 = 0$

$x + 1 - 1 = 0 - 1$ $x + 1 - 1 = 0 - 1$

$x = - 1$ $x = -1$

How do you solve using the quadratic formula x2−7x−8=0x^2-7x-8=0?