-8*x^2+48*x+320=0

Solution for -8*x^2+48*x+320=0 equation:

-8x^2+48x+320=0

a = -8; b = 48; c = +320;
Δ = b2-4ac
Δ = 482-4·(-8)·320
Δ = 12544
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12544}=112$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(48)-112}{2*-8}=\frac{-160}{-16}
=+10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(48)+112}{2*-8}=\frac{64}{-16}
=-4
$