-16x^2+108x+28=0

Solution for -16x^2+108x+28=0 equation:

-16x^2+108x+28=0

a = -16; b = 108; c = +28;
Δ = b2-4ac
Δ = 1082-4·(-16)·28
Δ = 13456
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{13456}=116$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(108)-116}{2*-16}=\frac{-224}{-32}
=+7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(108)+116}{2*-16}=\frac{8}{-32}
=-1/4
$