1)
7/13=140/260 =/= 14/20=91/260 (НЕВЕРНОЕ РАВЕНСТВО)
7/13 = 7*20/13*20 = 140/260
14/20 = 7*13/20*13 = 91/260
2)
1/9=3/27 = 3/27 (ВЕРНОЕ РАВЕНСТВО)
1/9 = 1*3/9*3 = 3/27
3/27
3)
5/8=15/24 =/= 9/12=18/24 (НЕВЕРНОЕ РАВЕНСТВО)
5/8 = 5*3/8/3 = 15/24
9/12 = 9*2/12*2 = 18/24
4)
2/10=12/60 =/= 10/60 (НЕВЕРНОЕ РАВЕНСТВО)
2/10 = 2*6/10*6 = 12/60
10/60