3x^2+36x=39

Solution for 3x^2+36x=39 equation:

3x^2+36x=39

We move all terms to the left:

3x^2+36x-(39)=0

a = 3; b = 36; c = -39;
Δ = b2-4ac
Δ = 362-4·3·(-39)
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(36)-42}{2*3}=\frac{-78}{6}
=-13
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+42}{2*3}=\frac{6}{6}
=1
$