3x(x+10)+5=11

Solution for 3x(x+10)+5=11 equation:

3x(x+10)+5=11

We move all terms to the left:

3x(x+10)+5-(11)=0

We add all the numbers together, and all the variables

3x(x+10)-6=0

We multiply parentheses

3x^2+30x-6=0

a = 3; b = 30; c = -6;
Δ = b2-4ac
Δ = 302-4·3·(-6)
Δ = 972
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:

$\sqrt{\Delta}=\sqrt{972}=\sqrt{324*3}=\sqrt{324}*\sqrt{3}=18\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-18\sqrt{3}}{2*3}=\frac{-30-18\sqrt{3}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+18\sqrt{3}}{2*3}=\frac{-30+18\sqrt{3}}{6}
$