There are two trees in a garden (a and b) and on both trees are some birds.
the birds in tree a say to the birds in tree b, "if one of you comes to our tree, then our population will be double that of yours."
but the birds in tree b counter, "if one of you comes here, then our population will be equal to that of yours."
how many birds are in each tree? (before the birds move around)
p. s. show your work