x^2-5=-2.75

Solution for x^2-5=-2.75 equation:

x^2-5=-2.75

We move all terms to the left:

x^2-5-(-2.75)=0

We add all the numbers together, and all the variables

x^2-2.25=0

a = 1; b = 0; c = -2.25;
Δ = b2-4ac
Δ = 02-4·1·(-2.25)
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

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