18.75=3b^2

Solution for 18.75=3b^2 equation:

18.75=3b^2

We move all terms to the left:

18.75-(3b^2)=0

a = -3; b = 0; c = +18.75;
Δ = b2-4ac
Δ = 02-4·(-3)·18.75
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-15}{2*-3}=\frac{-15}{-6}
=2+1/2
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+15}{2*-3}=\frac{15}{-6}
=-2+1/2
$