(2x)(x-7)=4x

Solution for (2x)(x-7)=4x equation:

(2x)(x-7)=4x

We move all terms to the left:

(2x)(x-7)-(4x)=0

We add all the numbers together, and all the variables

-4x+2x(x-7)=0

We multiply parentheses

2x^2-4x-14x=0

We add all the numbers together, and all the variables

2x^2-18x=0

a = 2; b = -18; c = 0;
Δ = b2-4ac
Δ = -182-4·2·0
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-18}{2*2}=\frac{0}{4}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+18}{2*2}=\frac{36}{4}
=9
$