15x^2+20x+5x=0

Solution for 15x^2+20x+5x=0 equation:

15x^2+20x+5x=0

We add all the numbers together, and all the variables

15x^2+25x=0

a = 15; b = 25; c = 0;
Δ = b2-4ac
Δ = 252-4·15·0
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-25}{2*15}=\frac{-50}{30}
=-1+2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+25}{2*15}=\frac{0}{30}
=0
$