Ответы и объяснения

2013-09-10T11:39:33+04:00
1) 1 1/4-5/14=5/4-5/14=35/28-10/28=25/28
2)(5/12)(2)=25/144
3)25/28:25/144=25/28*144/25=36/7
4)5/14+18/35=25/70+36/70=61/70
5)61/70+36/7=61/70+360/70=421/70=6 1/70