Найдите : 1)9/10от2/3; 2)3/16от4/9; 3)3/5от5/12; 4)3/4от8/15; 5)4/5от3/8; 6)5/7от14/25. решить. большое заранее.

1) 9\10*2\3=3\5

2)3\16*4\9=1\12
3)3\5*5\12=1\4
4)4\5*3\8=3\10

5)3\4*8\15=2\5
6)5\7*14/25=2\5

1/51 и 1/68 = 1/(3*17) и 1/(4*17) = 4/204 и 3/208
5/36 и 7/54 = 5/(2*2*9) и 7/(2*3*9) = 15/108 и 14/108
9/35 и 11/42 = 9/(7*5) и 11/(7*6) = 54/210 и 55/210
4/49 и 5/63 = 4/(7*7) и 5/(7*9) = 36/441 и 35/441
15/98 и 13/72 = 15/(2*49) и 13/(2*36) = 540/3528 и 637/3528