вычислите  (15 5/6 -9 25/27) - (2/3-5/18) + 7/27 + 13/18 

(15 5/6 -9 25/27) - (2/3-5/18) + 7/27 + 13/18 = 6 1/215 5/6-9 25/27=95/6-268/27=(855-536)/54=319/542/3-5/18=(12-5)/18=7/18319/54-7/18+7/27+13/18=(319-21+14+39)/54=351/54=6 1/2