2.x^2-x-11=0

Solution for 2.x^2-x-11=0 equation:

2.x^2-x-11=0

We add all the numbers together, and all the variables

2.x^2-1x-11=0

a = 2.; b = -1; c = -11;
Δ = b2-4ac
Δ = -12-4·2.·(-11)
Δ = 89
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{89}}{2*2.}=\frac{1-\sqrt{89}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{89}}{2*2.}=\frac{1+\sqrt{89}}{4}
$