X2+15x=324

Solution for X2+15x=324 equation:

X2+15X=324

We move all terms to the left:

X2+15X-(324)=0

We add all the numbers together, and all the variables

X^2+15X-324=0

a = 1; b = 15; c = -324;
Δ = b2-4ac
Δ = 152-4·1·(-324)
Δ = 1521
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1521}=39$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-39}{2*1}=\frac{-54}{2}
=-27
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+39}{2*1}=\frac{24}{2}
=12
$