А) 2/9+6/9-39; б)8 целых 25/27-(38/27+23/27)

А) 2/9 +6/9 -39=(2/9+6/9)-39=8/9-39=
= -38 (8/9-9/9)= -38 1/9
б) 8 25/27 - (38/27 +23/27)=
=8 25/27-( 61/27= 2 7/27)=
=6 (25/27-7/27)= 6 18/27= 6 6/9=6 2/3