1) 7\10 - 2\5 = 7\10 - 4\10 = 3\10 = 0.3 2) 2\3 + 7\8 = 16\24 + 21\24 = 37\24 = 1 целая 13\24 3) 3\4 - 1\6 = 9\12 - 2\12 = 7\12 4) 8\25 + 17\20 = 32\100 + 85\100 = 117\100 = 1.17