15x+3=20x2+4x

Solution for 15x+3=20x2+4x equation:

15x+3=20x^2+4x

We move all terms to the left:

15x+3-(20x^2+4x)=0

We get rid of parentheses

-20x^2+15x-4x+3=0

We add all the numbers together, and all the variables

-20x^2+11x+3=0

a = -20; b = 11; c = +3;
Δ = b2-4ac
Δ = 112-4·(-20)·3
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(11)-19}{2*-20}=\frac{-30}{-40}
=3/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+19}{2*-20}=\frac{8}{-40}
=-1/5
$