2(-2-4x)(2x-5)=0

Solution for 2(-2-4x)(2x-5)=0 equation:

2(-2-4x)(2x-5)=0

We add all the numbers together, and all the variables

2(-4x-2)(2x-5)=0

We multiply parentheses ..

2(-8x^2+20x-4x+10)=0

We multiply parentheses

-16x^2+40x-8x+20=0

We add all the numbers together, and all the variables

-16x^2+32x+20=0

a = -16; b = 32; c = +20;
Δ = b2-4ac
Δ = 322-4·(-16)·20
Δ = 2304
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2304}=48$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(32)-48}{2*-16}=\frac{-80}{-32}
=2+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(32)+48}{2*-16}=\frac{16}{-32}
=-1/2
$