(2x+5)*x=403

Solution for (2x+5)*x=403 equation:

(2x+5)*x=403

We move all terms to the left:

(2x+5)*x-(403)=0

We multiply parentheses

2x^2+5x-403=0

a = 2; b = 5; c = -403;
Δ = b2-4ac
Δ = 52-4·2·(-403)
Δ = 3249
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3249}=57$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-57}{2*2}=\frac{-62}{4}
=-15+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+57}{2*2}=\frac{52}{4}
=13
$