Сократите: а) 54/72; 75/120; 17/51; 150/180; б) 18*13 / 39/6; 6*35/42*12

а) 54 / 72 = 9 * 6 / (12 * 6) = 9 * 1 / (12 * 1) = 9 / 12 = 3 * 3 / (3 * 4) = 3 * 1 / (1 * 4) = 3 / 4 = 0.75;

75 / 120 = 3 * 25 / (3 * 40) = 25 / 40 = 5 * 5 / (5 * 8) = 5 / 8;

17 / 51 = 17 / (3 * 17) = 1 / (3 * 1) = 1 / 3;

150 / 180 = 15 * 10 / (18 * 10) = 15 / 18 = 3 * 5 / (6 * 3) = 5 / 6;

б) 18 * 13 / 39 / 6 = 18 * 13 * 6 / 39 = 18 * 13 * 6 / (13 * 3) = 18 * 6 / 3 = 6 * 6 = 36;

6 * 35 / 42 * 12 = 6 * 5 * 7 / (7 * 6 * 12) = 5 / 12.