81^2+b^2=225^2

Solution for 81^2+b^2=225^2 equation:

81^2+b^2=225^2

We move all terms to the left:

81^2+b^2-(225^2)=0

We add all the numbers together, and all the variables

b^2-44064=0

a = 1; b = 0; c = -44064;
Δ = b2-4ac
Δ = 02-4·1·(-44064)
Δ = 176256
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:

$\sqrt{\Delta}=\sqrt{176256}=\sqrt{5184*34}=\sqrt{5184}*\sqrt{34}=72\sqrt{34}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-72\sqrt{34}}{2*1}=\frac{0-72\sqrt{34}}{2}
=-\frac{72\sqrt{34}}{2}
=-36\sqrt{34}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+72\sqrt{34}}{2*1}=\frac{0+72\sqrt{34}}{2}
=\frac{72\sqrt{34}}{2}
=36\sqrt{34}
$