8x^2-28x=4x

Solution for 8x^2-28x=4x equation:

8x^2-28x=4x

We move all terms to the left:

8x^2-28x-(4x)=0

We add all the numbers together, and all the variables

8x^2-32x=0

a = 8; b = -32; c = 0;
Δ = b2-4ac
Δ = -322-4·8·0
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-32)-32}{2*8}=\frac{0}{16}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-32)+32}{2*8}=\frac{64}{16}
=4
$