2x(x+5)+3x=20

Solution for 2x(x+5)+3x=20 equation:

2x(x+5)+3x=20

We move all terms to the left:

2x(x+5)+3x-(20)=0

We add all the numbers together, and all the variables

3x+2x(x+5)-20=0

We multiply parentheses

2x^2+3x+10x-20=0

We add all the numbers together, and all the variables

2x^2+13x-20=0

a = 2; b = 13; c = -20;
Δ = b2-4ac
Δ = 132-4·2·(-20)
Δ = 329
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(13)-\sqrt{329}}{2*2}=\frac{-13-\sqrt{329}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(13)+\sqrt{329}}{2*2}=\frac{-13+\sqrt{329}}{4}
$