(1) (a^2 - 4a + 4) / (a^2 + 2a + 1) * (a + 1) / (a^2 - 4) = (a - 2)^2 / (a+1)^2 * (a+1) / (a + 2) (a - 2) = (a - 2) / (a + 2) (a + 1) = (a - 2) / (a^2 + 3a + 2)
(2) (y - 3) / (4y - 8) * (y - 2) / (y^2 - 9) = (y - 3) / 4(y - 2) * (y - 2) / (y + 3) (y - 3) = 1 / 4(y + 3) = 1 / (4y + 12)