28=16x-x2

Solution for 28=16x-x2 equation:

28=16x-x2

We move all terms to the left:

28-(16x-x2)=0

We add all the numbers together, and all the variables

-(+16x-1x^2)+28=0

We get rid of parentheses

1x^2-16x+28=0

We add all the numbers together, and all the variables

x^2-16x+28=0

a = 1; b = -16; c = +28;
Δ = b2-4ac
Δ = -162-4·1·28
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-12}{2*1}=\frac{4}{2}
=2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+12}{2*1}=\frac{28}{2}
=14
$