4x(x+15)=7x

Solution for 4x(x+15)=7x equation:

4x(x+15)=7x

We move all terms to the left:

4x(x+15)-(7x)=0

We add all the numbers together, and all the variables

-7x+4x(x+15)=0

We multiply parentheses

4x^2-7x+60x=0

We add all the numbers together, and all the variables

4x^2+53x=0

a = 4; b = 53; c = 0;
Δ = b2-4ac
Δ = 532-4·4·0
Δ = 2809
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2809}=53$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(53)-53}{2*4}=\frac{-106}{8}
=-13+1/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(53)+53}{2*4}=\frac{0}{8}
=0
$