204=(3x+5)(3x)

Solution for 204=(3x+5)(3x) equation:

204=(3x+5)(3x)

We move all terms to the left:

204-((3x+5)(3x))=0


We calculate terms in parentheses: -((3x+5)3x), so:

(3x+5)3x

We multiply parentheses

9x^2+15x

Back to the equation:

-(9x^2+15x)


We get rid of parentheses

-9x^2-15x+204=0

a = -9; b = -15; c = +204;
Δ = b2-4ac
Δ = -152-4·(-9)·204
Δ = 7569
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7569}=87$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-87}{2*-9}=\frac{-72}{-18}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+87}{2*-9}=\frac{102}{-18}
=-5+2/3
$