(5v-9)(2-v)=0

Solution for (5v-9)(2-v)=0 equation:

(5v-9)(2-v)=0

We add all the numbers together, and all the variables

(5v-9)(-1v+2)=0

We multiply parentheses ..

(-5v^2+10v+9v-18)=0

We get rid of parentheses

-5v^2+10v+9v-18=0

We add all the numbers together, and all the variables

-5v^2+19v-18=0

a = -5; b = 19; c = -18;
Δ = b2-4ac
Δ = 192-4·(-5)·(-18)
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(19)-1}{2*-5}=\frac{-20}{-10}
=+2
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(19)+1}{2*-5}=\frac{-18}{-10}
=1+4/5
$