Pomnóż ułamki: 2/3 * 1/7, 4/5 * 3/11, 1/3 * 1/4, 3/4 * 5/10, 3/5 * 1/6, 7/12 * 8/9, 6/9 * 4/7, 2/5 * 15/16, 4/5 * 1/6, 10/12 * 9/15, 3/14 * 21/22, 12/13 * 17/18, 2 * 5/7, 4/5 * 3, 4 * 3/2, 5/6 * 9, -5 * 4/5, 14/18 * 12, 1 1/2 * (-4/9), 1 1/5 * 1 7/8, 3 1/4 * 6, -9 * 1 7/18, 1 2/3 * 1 1/20, -30/14 * 7, 3/10 * 3 3/4, -3/7 * (-7/3).