0=5v^2-4

Solution for 0=5v^2-4 equation:

0=5v^2-4

We move all terms to the left:

0-(5v^2-4)=0

We add all the numbers together, and all the variables

-(5v^2-4)=0

We get rid of parentheses

-5v^2+4=0

a = -5; b = 0; c = +4;
Δ = b2-4ac
Δ = 02-4·(-5)·4
Δ = 80
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{80}=\sqrt{16*5}=\sqrt{16}*\sqrt{5}=4\sqrt{5}$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{5}}{2*-5}=\frac{0-4\sqrt{5}}{-10}
=-\frac{4\sqrt{5}}{-10}
=-\frac{2\sqrt{5}}{-5}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{5}}{2*-5}=\frac{0+4\sqrt{5}}{-10}
=\frac{4\sqrt{5}}{-10}
=\frac{2\sqrt{5}}{-5}
$