x^2+2x=3.24

Solution for x^2+2x=3.24 equation:

x^2+2x=3.24

We move all terms to the left:

x^2+2x-(3.24)=0

We add all the numbers together, and all the variables

x^2+2x-3.24=0

a = 1; b = 2; c = -3.24;
Δ = b2-4ac
Δ = 22-4·1·(-3.24)
Δ = 16.96
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-\sqrt{16.96}}{2*1}=\frac{-2-\sqrt{16.96}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+\sqrt{16.96}}{2*1}=\frac{-2+\sqrt{16.96}}{2}
$