(2v-5)(8+v)=0

Solution for (2v-5)(8+v)=0 equation:

(2v-5)(8+v)=0

We add all the numbers together, and all the variables

(2v-5)(v+8)=0

We multiply parentheses ..

(+2v^2+16v-5v-40)=0

We get rid of parentheses

2v^2+16v-5v-40=0

We add all the numbers together, and all the variables

2v^2+11v-40=0

a = 2; b = 11; c = -40;
Δ = b2-4ac
Δ = 112-4·2·(-40)
Δ = 441
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{441}=21$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(11)-21}{2*2}=\frac{-32}{4}
=-8
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(11)+21}{2*2}=\frac{10}{4}
=2+1/2
$