(15x-5)(3-4x)=0

Solution for (15x-5)(3-4x)=0 equation:

(15x-5)(3-4x)=0

We add all the numbers together, and all the variables

(15x-5)(-4x+3)=0

We multiply parentheses ..

(-60x^2+45x+20x-15)=0

We get rid of parentheses

-60x^2+45x+20x-15=0

We add all the numbers together, and all the variables

-60x^2+65x-15=0

a = -60; b = 65; c = -15;
Δ = b2-4ac
Δ = 652-4·(-60)·(-15)
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{-(65)-25}{2*-60}=\frac{-90}{-120}
=3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(65)+25}{2*-60}=\frac{-40}{-120}
=1/3
$