Помогите пжл 2 1/7 : 15 1 7/9 : 8 3 1/8 : 5 4 1/2 : 6 5 1/4 : 7 5 1/7 : 12 /-это дробная линия

1) 2 1/7 : 15 = 15/7 * 1/15 = (15 * 1)/(7 * 15) = (1 * 1)/(7 * 1) = 1/7; 2) 1 7/9 : 8 = 16/9 * 1/8 = (16 * 1)/(9 * 8) = (2 * 1)/(9 * 1) = 2/9; 3) 3 1/8 : 5 = 25/8 * 1/5 = (25 * 1)/(8 * 5) = (5 * 1)/(8 * 1) = 5/8; 4) 4 1/2 : 6 = 9/2 * 1/6 = (9 * 1)/(2 * 6) = (3 * 1)/(2 * 2) = 3/4; 5) 5 1/4 : 7 = 21/4 * 1/7 = (21 * 1)/(4 * 7) = (3 * 1)/(4 * 1) = 3/4; 6) 5 1/7 : 12 = 36/7 * 1/12 = (36 * 1)/(7 * 12) = (3 * 1)/(7 * 1) = 3/7.