Question 889086
{{{A=2B-4}}}
{{{A^2+B^2=100}}}
Substitute from the first equation into the second,
{{{(2B-4)^2+B^2=100}}}
{{{4B^2-16B+16+B^2-100=0}}}
{{{5B^2-16B-84=0}}}
{{{(5B+14)(B-6)=0}}}
We're only interested in the integer solution.
{{{B-6=0}}}
{{{highlight(B=6)}}}
Then,
{{{A=2(6)-4}}}
{{{A=12-4}}}
{{{highlight(A=8)}}}