(-3n-8)(2n+4)=0.

Solution for (-3n-8)(2n+4)=0. equation:

(-3n-8)(2n+4)=0.

We multiply parentheses ..

(-6n^2-12n-16n-32)=0

We get rid of parentheses

-6n^2-12n-16n-32=0

We add all the numbers together, and all the variables

-6n^2-28n-32=0

a = -6; b = -28; c = -32;
Δ = b2-4ac
Δ = -282-4·(-6)·(-32)
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-28)-4}{2*-6}=\frac{24}{-12}
=-2
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+4}{2*-6}=\frac{32}{-12}
=-2+2/3
$