520=(4x+3)x

Solution for 520=(4x+3)x equation:

520=(4x+3)x

We move all terms to the left:

520-((4x+3)x)=0


We calculate terms in parentheses: -((4x+3)x), so:

(4x+3)x

We multiply parentheses

4x^2+3x

Back to the equation:

-(4x^2+3x)


We get rid of parentheses

-4x^2-3x+520=0

a = -4; b = -3; c = +520;
Δ = b2-4ac
Δ = -32-4·(-4)·520
Δ = 8329
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{8329}}{2*-4}=\frac{3-\sqrt{8329}}{-8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+\sqrt{8329}}{2*-4}=\frac{3+\sqrt{8329}}{-8}
$