2x^2+3x=399

Solution for 2x^2+3x=399 equation:

2x^2+3x=399

We move all terms to the left:

2x^2+3x-(399)=0

a = 2; b = 3; c = -399;
Δ = b2-4ac
Δ = 32-4·2·(-399)
Δ = 3201
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{-(3)-\sqrt{3201}}{2*2}=\frac{-3-\sqrt{3201}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{3201}}{2*2}=\frac{-3+\sqrt{3201}}{4}
$