8u2=72

Solution for 8u2=72 equation:

8u^2=72

We move all terms to the left:

8u^2-(72)=0

a = 8; b = 0; c = -72;
Δ = b2-4ac
Δ = 02-4·8·(-72)
Δ = 2304
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2304}=48$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-48}{2*8}=\frac{-48}{16}
=-3
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+48}{2*8}=\frac{48}{16}
=3
$