b2=4.5

Solution for b2=4.5 equation:

b2=4.5

We move all terms to the left:

b2-(4.5)=0

We add all the numbers together, and all the variables

b^2-4.5=0

a = 1; b = 0; c = -4.5;
Δ = b2-4ac
Δ = 02-4·1·(-4.5)
Δ = 18
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{18}=\sqrt{9*2}=\sqrt{9}*\sqrt{2}=3\sqrt{2}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-3\sqrt{2}}{2*1}=\frac{0-3\sqrt{2}}{2}
=-\frac{3\sqrt{2}}{2}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+3\sqrt{2}}{2*1}=\frac{0+3\sqrt{2}}{2}
=\frac{3\sqrt{2}}{2}
$