0.2815=0.4027-0.0112x+0.0001x^2

Solution for 0.2815=0.4027-0.0112x+0.0001x^2 equation:

0.2815=0.4027-0.0112x+0.0001x^2

We move all terms to the left:

0.2815-(0.4027-0.0112x+0.0001x^2)=0

We get rid of parentheses

-0.0001x^2+0.0112x-0.4027+0.2815=0

We add all the numbers together, and all the variables

-0.0001x^2+0.0112x-0.1212=0

a = -0.0001; b = 0.0112; c = -0.1212;
Δ = b2-4ac
Δ = 0.01122-4·(-0.0001)·(-0.1212)
Δ = 7.696E-5
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{-(0.0112)-\sqrt{7.696E-5}}{2*-0.0001}=\frac{-0.0112-\sqrt{7.696E-5}}{-0.0002}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.0112)+\sqrt{7.696E-5}}{2*-0.0001}=\frac{-0.0112+\sqrt{7.696E-5}}{-0.0002}
$