9/10 от 2/3 3 3/16 от 4/9 3/5 от 5/12 3/4 от 8/15 4/5 от 3/8 5/7 от 14/25

1) 9/10 * 2/3 = (9 * 2)/(10 * 3) = (3 * 1)/(5 * 1) = 3/5; 2) 3/16 * 4/9 = (3 * 4)/(16 * 9) = (1 * 1)/(4 * 3) = 1/12; 3) 3/5 * 5/12 = (3 * 5)/(5 * 12) = (1 * 1)/(1 * 4) = 1/4; 4) 3/4 * 8/15 = (3 * 8)/(4 * 15) = (1 * 2)/(1 * 5) = 2/5; 5) 4/5 * 3/8 = (4 * 3)/(5 * 8) = (1 * 3)/(5 * 2) = 3/10; 6) 5/7 * 14/25 = (5 * 14)/(7 * 25) = (1 * 7)/(1 * 5) = 7/5 = 1 2/5.