x^2+3x=3600

Solution for x^2+3x=3600 equation:

x^2+3x=3600

We move all terms to the left:

x^2+3x-(3600)=0

a = 1; b = 3; c = -3600;
Δ = b2-4ac
Δ = 32-4·1·(-3600)
Δ = 14409
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{14409}=\sqrt{9*1601}=\sqrt{9}*\sqrt{1601}=3\sqrt{1601}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-3\sqrt{1601}}{2*1}=\frac{-3-3\sqrt{1601}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+3\sqrt{1601}}{2*1}=\frac{-3+3\sqrt{1601}}{2}
$