13=x2+12x

Solution for 13=x2+12x equation:

13=x2+12x

We move all terms to the left:

13-(x2+12x)=0

We add all the numbers together, and all the variables

-(+x^2+12x)+13=0

We get rid of parentheses

-x^2-12x+13=0

We add all the numbers together, and all the variables

-1x^2-12x+13=0

a = -1; b = -12; c = +13;
Δ = b2-4ac
Δ = -122-4·(-1)·13
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-14}{2*-1}=\frac{-2}{-2}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+14}{2*-1}=\frac{26}{-2}
=-13
$