Squaring the first equation gives [(x+y)^2=x^2+2xy+y^2,]so 102=32+2xy or 2xy=26. Dividing both sides of x+y=10 by 2, we get x/2+y/2=5, so x+y=10. Thus, (x,y) lies on the line y=10−x. Also, since 2xy=26, xy=13, so (x,y) lies on the hyperbola xy=13. The solutions are (x,y)=(2,8), (−2,12), (4,6), (−4,14).
Therefore, the ordered pairs (x,y) are (2,8),(4,6),(8,2),(12,−2),(14,−4)