4x2+20x+13=0

Solution for 4x2+20x+13=0 equation:

4x^2+20x+13=0

a = 4; b = 20; c = +13;
Δ = b2-4ac
Δ = 202-4·4·13
Δ = 192
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:

$\sqrt{\Delta}=\sqrt{192}=\sqrt{64*3}=\sqrt{64}*\sqrt{3}=8\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-8\sqrt{3}}{2*4}=\frac{-20-8\sqrt{3}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+8\sqrt{3}}{2*4}=\frac{-20+8\sqrt{3}}{8}
$