-2v=-7v^2

Solution for -2v=-7v^2 equation:

-2v=-7v^2

We move all terms to the left:

-2v-(-7v^2)=0

We get rid of parentheses

7v^2-2v=0

a = 7; b = -2; c = 0;
Δ = b2-4ac
Δ = -22-4·7·0
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-2}{2*7}=\frac{0}{14}
=0
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+2}{2*7}=\frac{4}{14}
=2/7
$