X^2+12x=864

Solution for X^2+12x=864 equation:

X^2+12X=864

We move all terms to the left:

X^2+12X-(864)=0

a = 1; b = 12; c = -864;
Δ = b2-4ac
Δ = 122-4·1·(-864)
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(12)-60}{2*1}=\frac{-72}{2}
=-36
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(12)+60}{2*1}=\frac{48}{2}
=24
$