171=(x+3)(3x)

Solution for 171=(x+3)(3x) equation:

171=(x+3)(3x)

We move all terms to the left:

171-((x+3)(3x))=0


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

(x+3)3x

We multiply parentheses

3x^2+9x

Back to the equation:

-(3x^2+9x)


We get rid of parentheses

-3x^2-9x+171=0

a = -3; b = -9; c = +171;
Δ = b2-4ac
Δ = -92-4·(-3)·171
Δ = 2133
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2133}=\sqrt{9*237}=\sqrt{9}*\sqrt{237}=3\sqrt{237}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-3\sqrt{237}}{2*-3}=\frac{9-3\sqrt{237}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+3\sqrt{237}}{2*-3}=\frac{9+3\sqrt{237}}{-6}
$