№2. Выполните действия: а) (30rac{16}{43} + 42rac{19}{43} + 9rac{8}{43}) б) (4rac{112}{113} + 7rac{101}{113}) в) (21rac{29}{48} - 4rac{5}{48}) г) (180rac{}{}-rac{179}{180}) д) (23rac{4}{19} - 22rac{7}{19})

а) (30rac{16}{43} + 42rac{19}{43} + 9rac{8}{43} = (30+42+9) + (rac{16}{43} + rac{19}{43} + rac{8}{43}) = 81 + rac{16+19+8}{43} = 81 + rac{43}{43} = 81 + 1 = 82) б) (4rac{112}{113} + 7rac{101}{113} = (4+7) + (rac{112}{113} + rac{101}{113}) = 11 + rac{112+101}{113} = 11 + rac{213}{113} = 11 + 1rac{100}{113} = 12rac{100}{113}) в) (21rac{29}{48} - 4rac{5}{48} = (21-4) + (rac{29}{48} - rac{5}{48}) = 17 + rac{29-5}{48} = 17 + rac{24}{48} = 17 + rac{1}{2} = 17rac{1}{2}) г) (180 - rac{179}{180} = 179rac{180}{180} - rac{179}{180} = 179rac{180-179}{180} = 179rac{1}{180}) д) (23rac{4}{19} - 22rac{7}{19} = (23-22) + (rac{4}{19} - rac{7}{19}) = 1 - rac{3}{19} = rac{19}{19} - rac{3}{19} = rac{16}{19})