Reginald De Koven[?]
Rudolf Friml[?]
Victor Herbert
Emmerich Kalman[?], also known as Imre Kálmán
Franz Lehar
Jacques Offenbach
Sigmund Romberg[?]
Johann Strauss II
Arthur S. Sullivan (of Gilbert and Sullivan)
... on x) to the expression to the left of "=", that will make it a perfect square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = ...