12r2=36+104r

Solution for 12r2=36+104r equation:

12r^2=36+104r

We move all terms to the left:

12r^2-(36+104r)=0

We add all the numbers together, and all the variables

12r^2-(104r+36)=0

We get rid of parentheses

12r^2-104r-36=0

a = 12; b = -104; c = -36;
Δ = b2-4ac
Δ = -1042-4·12·(-36)
Δ = 12544
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12544}=112$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-104)-112}{2*12}=\frac{-8}{24}
=-1/3
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-104)+112}{2*12}=\frac{216}{24}
=9
$