x^2=9^2+40^2

Solution for x^2=9^2+40^2 equation:

x^2=9^2+40^2

We move all terms to the left:

x^2-(9^2+40^2)=0

We add all the numbers together, and all the variables

x^2-1681=0

a = 1; b = 0; c = -1681;
Δ = b2-4ac
Δ = 02-4·1·(-1681)
Δ = 6724
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6724}=82$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-82}{2*1}=\frac{-82}{2}
=-41
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+82}{2*1}=\frac{82}{2}
=41
$