3000=0.042v2

Solution for 3000=0.042v2 equation:

3000=0.042v^2

We move all terms to the left:

3000-(0.042v^2)=0

We get rid of parentheses

-0.042v^2+3000=0

a = -0.042; b = 0; c = +3000;
Δ = b2-4ac
Δ = 02-4·(-0.042)·3000
Δ = 504
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:

$\sqrt{\Delta}=\sqrt{504}=\sqrt{4*126}=\sqrt{4}*\sqrt{126}=2\sqrt{126}$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{126}}{2*-0.042}=\frac{0-2\sqrt{126}}{-0.084}
=-\frac{2\sqrt{126}}{-0.084}
=-\frac{\sqrt{126}}{-0.042}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{126}}{2*-0.042}=\frac{0+2\sqrt{126}}{-0.084}
=\frac{2\sqrt{126}}{-0.084}
=\frac{\sqrt{126}}{-0.042}
$