8x^2-16x-55=0

Solution for 8x^2-16x-55=0 equation:

8x^2-16x-55=0

a = 8; b = -16; c = -55;
Δ = b2-4ac
Δ = -162-4·8·(-55)
Δ = 2016
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:

$\sqrt{\Delta}=\sqrt{2016}=\sqrt{144*14}=\sqrt{144}*\sqrt{14}=12\sqrt{14}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-12\sqrt{14}}{2*8}=\frac{16-12\sqrt{14}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+12\sqrt{14}}{2*8}=\frac{16+12\sqrt{14}}{16}
$