4x^2+56x-144=0

Solution for 4x^2+56x-144=0 equation:

4x^2+56x-144=0

a = 4; b = 56; c = -144;
Δ = b2-4ac
Δ = 562-4·4·(-144)
Δ = 5440
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:

$\sqrt{\Delta}=\sqrt{5440}=\sqrt{64*85}=\sqrt{64}*\sqrt{85}=8\sqrt{85}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(56)-8\sqrt{85}}{2*4}=\frac{-56-8\sqrt{85}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56)+8\sqrt{85}}{2*4}=\frac{-56+8\sqrt{85}}{8}
$