(4v-3)(9-v)=0

Solution for (4v-3)(9-v)=0 equation:

(4v-3)(9-v)=0

We add all the numbers together, and all the variables

(4v-3)(-1v+9)=0

We multiply parentheses ..

(-4v^2+36v+3v-27)=0

We get rid of parentheses

-4v^2+36v+3v-27=0

We add all the numbers together, and all the variables

-4v^2+39v-27=0

a = -4; b = 39; c = -27;
Δ = b2-4ac
Δ = 392-4·(-4)·(-27)
Δ = 1089
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1089}=33$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(39)-33}{2*-4}=\frac{-72}{-8}
=+9
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(39)+33}{2*-4}=\frac{-6}{-8}
=3/4
$