840=22x2+8x

Solution for 840=22x2+8x equation:

840=22x^2+8x

We move all terms to the left:

840-(22x^2+8x)=0

We get rid of parentheses

-22x^2-8x+840=0

a = -22; b = -8; c = +840;
Δ = b2-4ac
Δ = -82-4·(-22)·840
Δ = 73984
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{73984}=272$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-272}{2*-22}=\frac{-264}{-44}
=+6
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+272}{2*-22}=\frac{280}{-44}
=-6+4/11
$