3x+2x(x+4)=13

Solution for 3x+2x(x+4)=13 equation:

3x+2x(x+4)=13

We move all terms to the left:

3x+2x(x+4)-(13)=0

We multiply parentheses

2x^2+3x+8x-13=0

We add all the numbers together, and all the variables

2x^2+11x-13=0

a = 2; b = 11; c = -13;
Δ = b2-4ac
Δ = 112-4·2·(-13)
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(11)-15}{2*2}=\frac{-26}{4}
=-6+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+15}{2*2}=\frac{4}{4}
=1
$