612=x^2+16x

Solution for 612=x^2+16x equation:

612=x^2+16x

We move all terms to the left:

612-(x^2+16x)=0

We get rid of parentheses

-x^2-16x+612=0

We add all the numbers together, and all the variables

-1x^2-16x+612=0

a = -1; b = -16; c = +612;
Δ = b2-4ac
Δ = -162-4·(-1)·612
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-52}{2*-1}=\frac{-36}{-2}
=+18
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+52}{2*-1}=\frac{68}{-2}
=-34
$