Question 477301
{{{x^2 + (x+2)^2 = (x+4)^2 + 9}}}
==> {{{x^2 + x^2 + 4x + 4 = x^2 + 8x + 16 + 9}}}

==> {{{x^2 - 4x - 21 = 0}}}

<==> (x - 7 )(x  + 3 ) = 0 ==> x = 7, -3.
Eliminate -3 because it is not non-negative.

==> the numbers are 7,9, 11.