V=(8v-6)(7v+6)

Solution for V=(8v-6)(7v+6) equation:

=(8V-6)(7V+6)

We move all terms to the left:

-((8V-6)(7V+6))=0

We multiply parentheses ..

-((+56V^2+48V-42V-36))=0


We calculate terms in parentheses: -((+56V^2+48V-42V-36)), so:

(+56V^2+48V-42V-36)

We get rid of parentheses

56V^2+48V-42V-36

We add all the numbers together, and all the variables

56V^2+6V-36

Back to the equation:

-(56V^2+6V-36)


We get rid of parentheses

-56V^2-6V+36=0

a = -56; b = -6; c = +36;
Δ = b2-4ac
Δ = -62-4·(-56)·36
Δ = 8100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$V_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$V_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8100}=90$
$V_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-90}{2*-56}=\frac{-84}{-112}
=3/4
$
$V_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+90}{2*-56}=\frac{96}{-112}
=-6/7
$