3x(x+11)=-15

Solution for 3x(x+11)=-15 equation:

3x(x+11)=-15

We move all terms to the left:

3x(x+11)-(-15)=0

We add all the numbers together, and all the variables

3x(x+11)+15=0

We multiply parentheses

3x^2+33x+15=0

a = 3; b = 33; c = +15;
Δ = b2-4ac
Δ = 332-4·3·15
Δ = 909
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:

$\sqrt{\Delta}=\sqrt{909}=\sqrt{9*101}=\sqrt{9}*\sqrt{101}=3\sqrt{101}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(33)-3\sqrt{101}}{2*3}=\frac{-33-3\sqrt{101}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(33)+3\sqrt{101}}{2*3}=\frac{-33+3\sqrt{101}}{6}
$