6v^2-21=10v

Solution for 6v^2-21=10v equation:

6v^2-21=10v

We move all terms to the left:

6v^2-21-(10v)=0

a = 6; b = -10; c = -21;
Δ = b2-4ac
Δ = -102-4·6·(-21)
Δ = 604
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:

$\sqrt{\Delta}=\sqrt{604}=\sqrt{4*151}=\sqrt{4}*\sqrt{151}=2\sqrt{151}$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-2\sqrt{151}}{2*6}=\frac{10-2\sqrt{151}}{12}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+2\sqrt{151}}{2*6}=\frac{10+2\sqrt{151}}{12}
$