8x^2-16x-30=0

Solution for 8x^2-16x-30=0 equation:

8x^2-16x-30=0

a = 8; b = -16; c = -30;
Δ = b2-4ac
Δ = -162-4·8·(-30)
Δ = 1216
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:

$\sqrt{\Delta}=\sqrt{1216}=\sqrt{64*19}=\sqrt{64}*\sqrt{19}=8\sqrt{19}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-8\sqrt{19}}{2*8}=\frac{16-8\sqrt{19}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+8\sqrt{19}}{2*8}=\frac{16+8\sqrt{19}}{16}
$