(3x+3)(x)=165

Solution for (3x+3)(x)=165 equation:

(3x+3)(x)=165

We move all terms to the left:

(3x+3)(x)-(165)=0

We multiply parentheses

3x^2+3x-165=0

a = 3; b = 3; c = -165;
Δ = b2-4ac
Δ = 32-4·3·(-165)
Δ = 1989
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:

$\sqrt{\Delta}=\sqrt{1989}=\sqrt{9*221}=\sqrt{9}*\sqrt{221}=3\sqrt{221}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-3\sqrt{221}}{2*3}=\frac{-3-3\sqrt{221}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+3\sqrt{221}}{2*3}=\frac{-3+3\sqrt{221}}{6}
$