4(v-5)(-v+8)=0

Solution for 4(v-5)(-v+8)=0 equation:

4(v-5)(-v+8)=0

We add all the numbers together, and all the variables

4(v-5)(-1v+8)=0

We multiply parentheses ..

4(-1v^2+8v+5v-40)=0

We multiply parentheses

-4v^2+32v+20v-160=0

We add all the numbers together, and all the variables

-4v^2+52v-160=0

a = -4; b = 52; c = -160;
Δ = b2-4ac
Δ = 522-4·(-4)·(-160)
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(52)-12}{2*-4}=\frac{-64}{-8}
=+8
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(52)+12}{2*-4}=\frac{-40}{-8}
=+5
$