(1/4 - 2/3) * (4/5 - 2/15) * (- 3/5) = (3/12 - 8/12) * (12/15 - 2/15) * (- 3/5) = -5/12 * 10/15 * (- 3/5) = - 1/6 * 5/3 * (- 3/5) = - 5/18 * (- 3/5) = 1/6
(1/6 - 5/9) * (1/2 - 3/7) * 7 1/5 = (3/18 - 10/18) * (7/14 - 6/14) * 7 1/5 = - 7/18 * 1/14 * 7 1/5 = - 1/18 * 1/2 * 7 1/5 = - 1/36 * 7 1/5 = - 1/36 * 36/5 = - 1/5