4x2-x-13=0

Solution for 4x2-x-13=0 equation:

4x^2-x-13=0

We add all the numbers together, and all the variables

4x^2-1x-13=0

a = 4; b = -1; c = -13;
Δ = b2-4ac
Δ = -12-4·4·(-13)
Δ = 209
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{209}}{2*4}=\frac{1-\sqrt{209}}{8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{209}}{2*4}=\frac{1+\sqrt{209}}{8}
$