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

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

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

We add all the numbers together, and all the variables

-4(w+7)(-1w+8)=0

We multiply parentheses ..

-4(-1w^2+8w-7w+56)=0

We multiply parentheses

4w^2-32w+28w-224=0

We add all the numbers together, and all the variables

4w^2-4w-224=0

a = 4; b = -4; c = -224;
Δ = b2-4ac
Δ = -42-4·4·(-224)
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

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