16v^2-21=0

Solution for 16v^2-21=0 equation:

16v^2-21=0

a = 16; b = 0; c = -21;
Δ = b2-4ac
Δ = 02-4·16·(-21)
Δ = 1344
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:

$\sqrt{\Delta}=\sqrt{1344}=\sqrt{64*21}=\sqrt{64}*\sqrt{21}=8\sqrt{21}$
$v_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-8\sqrt{21}}{2*16}=\frac{0-8\sqrt{21}}{32}
=-\frac{8\sqrt{21}}{32}
=-\frac{\sqrt{21}}{4}
$
$v_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+8\sqrt{21}}{2*16}=\frac{0+8\sqrt{21}}{32}
=\frac{8\sqrt{21}}{32}
=\frac{\sqrt{21}}{4}
$