29^2=20^2+x^2

Solution for 29^2=20^2+x^2 equation:

29^2=20^2+x^2

We move all terms to the left:

29^2-(20^2+x^2)=0

We add all the numbers together, and all the variables

-(20^2+x^2)+841=0

We get rid of parentheses

-x^2+841-20^2=0

We add all the numbers together, and all the variables

-1x^2+441=0

a = -1; b = 0; c = +441;
Δ = b2-4ac
Δ = 02-4·(-1)·441
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-42}{2*-1}=\frac{-42}{-2}
=+21
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+42}{2*-1}=\frac{42}{-2}
=-21
$