(4-4x)(8x+7)=0

Solution for (4-4x)(8x+7)=0 equation:

(4-4x)(8x+7)=0

We add all the numbers together, and all the variables

(-4x+4)(8x+7)=0

We multiply parentheses ..

(-32x^2-28x+32x+28)=0

We get rid of parentheses

-32x^2-28x+32x+28=0

We add all the numbers together, and all the variables

-32x^2+4x+28=0

a = -32; b = 4; c = +28;
Δ = b2-4ac
Δ = 42-4·(-32)·28
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-60}{2*-32}=\frac{-64}{-64}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+60}{2*-32}=\frac{56}{-64}
=-7/8
$