0=-64x^2-96x+640

Solution for 0=-64x^2-96x+640 equation:

0=-64x^2-96x+640

We move all terms to the left:

0-(-64x^2-96x+640)=0

We add all the numbers together, and all the variables

-(-64x^2-96x+640)=0

We get rid of parentheses

64x^2+96x-640=0

a = 64; b = 96; c = -640;
Δ = b2-4ac
Δ = 962-4·64·(-640)
Δ = 173056
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{173056}=416$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(96)-416}{2*64}=\frac{-512}{128}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(96)+416}{2*64}=\frac{320}{128}
=2+1/2
$