Answer :
This expression is the difference of two squares.
It can be rewritten as (x/9)^2 - (y/10)^2.
The factors are [(x/9) - (y/10)] [(x/9) + (y/10)].
It can be rewritten as (x/9)^2 - (y/10)^2.
The factors are [(x/9) - (y/10)] [(x/9) + (y/10)].