-16X^2+8x+40=0

Solution for -16X^2+8x+40=0 equation:

-16X^2+8X+40=0

a = -16; b = 8; c = +40;
Δ = b2-4ac
Δ = 82-4·(-16)·40
Δ = 2624
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2624}=\sqrt{64*41}=\sqrt{64}*\sqrt{41}=8\sqrt{41}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-8\sqrt{41}}{2*-16}=\frac{-8-8\sqrt{41}}{-32}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+8\sqrt{41}}{2*-16}=\frac{-8+8\sqrt{41}}{-32}
$