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

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

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

We add all the numbers together, and all the variables

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

We multiply parentheses ..

-7(+28x^2-32x)=0

We multiply parentheses

-196x^2+224x=0

a = -196; b = 224; c = 0;
Δ = b2-4ac
Δ = 2242-4·(-196)·0
Δ = 50176
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{50176}=224$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(224)-224}{2*-196}=\frac{-448}{-392}
=1+1/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(224)+224}{2*-196}=\frac{0}{-392}
=0
$