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

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

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

We add all the numbers together, and all the variables

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

We multiply parentheses ..

(+5v^2+8v+20v+32)=0

We get rid of parentheses

5v^2+8v+20v+32=0

We add all the numbers together, and all the variables

5v^2+28v+32=0

a = 5; b = 28; c = +32;
Δ = b2-4ac
Δ = 282-4·5·32
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{-(28)-12}{2*5}=\frac{-40}{10}
=-4
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+12}{2*5}=\frac{-16}{10}
=-1+3/5
$