Ответы и объяснения

2014-03-01T13:47:16+00:00
3ц1/2-5/9 = 7/2 - 5/9 = 63/9 - 5/9 = 58/9 = 6 4/9
1ц1/3-1/3 = 4/3 - 1/3 = 3/3 = 1
1ц13/15-2/5
= 28/15 - 2/5 = 28/15 - 6/15 = 22/15 = 1 7/15