D+5=14x2

Solution for D+5=14x2 equation:

+5=14D^2

We move all terms to the left:

+5-(14D^2)=0

a = -14; b = 0; c = +5;
Δ = b2-4ac
Δ = 02-4·(-14)·5
Δ = 280
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$D_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$D_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{280}=\sqrt{4*70}=\sqrt{4}*\sqrt{70}=2\sqrt{70}$
$D_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{70}}{2*-14}=\frac{0-2\sqrt{70}}{-28}
=-\frac{2\sqrt{70}}{-28}
=-\frac{\sqrt{70}}{-14}
$
$D_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{70}}{2*-14}=\frac{0+2\sqrt{70}}{-28}
=\frac{2\sqrt{70}}{-28}
=\frac{\sqrt{70}}{-14}
$