4x2+28x-27=0

Solution for 4x2+28x-27=0 equation:

4x^2+28x-27=0

a = 4; b = 28; c = -27;
Δ = b2-4ac
Δ = 282-4·4·(-27)
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{-(28)-8\sqrt{19}}{2*4}=\frac{-28-8\sqrt{19}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+8\sqrt{19}}{2*4}=\frac{-28+8\sqrt{19}}{8}
$