8x2-30x-27=0

Solution for 8x2-30x-27=0 equation:

8x^2-30x-27=0

a = 8; b = -30; c = -27;
Δ = b2-4ac
Δ = -302-4·8·(-27)
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-42}{2*8}=\frac{-12}{16}
=-3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+42}{2*8}=\frac{72}{16}
=4+1/2
$