-10=-14v*14v

Solution for -10=-14v*14v equation:

-10=-14v*14v

We move all terms to the left:

-10-(-14v*14v)=0

We get rid of parentheses

14v*14v-10=0

Wy multiply elements

196v^2-10=0

a = 196; b = 0; c = -10;
Δ = b2-4ac
Δ = 02-4·196·(-10)
Δ = 7840
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:

$\sqrt{\Delta}=\sqrt{7840}=\sqrt{784*10}=\sqrt{784}*\sqrt{10}=28\sqrt{10}$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-28\sqrt{10}}{2*196}=\frac{0-28\sqrt{10}}{392}
=-\frac{28\sqrt{10}}{392}
=-\frac{\sqrt{10}}{14}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+28\sqrt{10}}{2*196}=\frac{0+28\sqrt{10}}{392}
=\frac{28\sqrt{10}}{392}
=\frac{\sqrt{10}}{14}
$