An Italian-American is an American of Italian descent. Although proud of their heritage most prefer to be called simply American. Much Italian immigration to the United States took place in the late 19th century and early 20th century.
... "=", 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 = b/(2a), so we add the square of b/(2a) ...