-16x^2+64x+336=0

Solution for -16x^2+64x+336=0 equation:

-16x^2+64x+336=0

a = -16; b = 64; c = +336;
Δ = b2-4ac
Δ = 642-4·(-16)·336
Δ = 25600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25600}=160$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(64)-160}{2*-16}=\frac{-224}{-32}
=+7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(64)+160}{2*-16}=\frac{96}{-32}
=-3
$