72=32b^2

Solution for 72=32b^2 equation:

72=32b^2

We move all terms to the left:

72-(32b^2)=0

a = -32; b = 0; c = +72;
Δ = b2-4ac
Δ = 02-4·(-32)·72
Δ = 9216
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9216}=96$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-96}{2*-32}=\frac{-96}{-64}
=1+1/2
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+96}{2*-32}=\frac{96}{-64}
=-1+1/2
$