299
15/36=5/12
42/45=14/15
25/100=1/4
9/30=3/10
теперь приводим к общему знаменателю 60
5/12=25/60
14/15=56/60
1/4=15/60
3/10=18/60
300.
5/7 и 1/2=10/14 и 7/14
7/20и 1/15=21/60и 4/60
3/26и 5/39=117/1014и 130/1014
8/11и 5/8=65/88и 55/88
7/13и 2/11=77/143и 26/143
3/22и 2/33=9/66и 4/66
7/60, 13/540 и 9/20=63/540, 13/540 и 243/540
52/105,4/95 и 61/63=2964/5985, 252/5985 и 5795/5985