Dmitry B. answered 04/25/20
Five years of Prealgebra tutoring at a math group
I don't really see what kind of problem you can have here. You can solve this by algebra, but you don't need to. Simply pickup 2 numbers, so their sum will be 19, say 10 and 9 and go from there. It's irony and pure incident I appear puck up an answer righ away. So it took me 10 seconds and pure luck to solve this, why you didnt try it?