AB is 10 units
10^2=100
You need 2 squared numbers that add or subtract to 100 (pythagoras's theorum)They will be the distances from A to X and B to X
You should be able to take it from there,
Approach this by first drawing circles centred on point (-5,0) of radii 1, 2, 3 ... 10.
Then draw circles centred on point (5,0) with the same radii.
At the points where these circles intersect the distance from A is a positive integer less than or equal to 10, as is the distance from B.
It is a simple matter to count these intersection points. There are, indeed, 119 of them.
My goodness. That person has taken way too many psychedelic drugs!
Thanks Alan :))