Find all pairs of real numbers $(x, y)$ that satisfy the equation $(x + y)^2 = (x + 3) (y - 3)$.
Problem
Source: 2005 Estonia National Olympiad Final Round grade 9 p4
Tags: equation, algebra, trinomial
Source: 2005 Estonia National Olympiad Final Round grade 9 p4
Tags: equation, algebra, trinomial
Find all pairs of real numbers $(x, y)$ that satisfy the equation $(x + y)^2 = (x + 3) (y - 3)$.