А)-3/7+2/3= б)2/9+(-5/9))+2/3 в)(0,8+(-1/6))+(-2 1/3)=

а)-3/7+2/3= -9/21+14/21=5/21
б)2/9+(-5/9))+2/3 = -3/9 + 2/3= -3/9+6/9=3/9
в)(0,8+(-1/6))+(-2 1/3)= (8/10 - 1/6) + 7/3= (4/5 - 1/6) +7/3= 24/30 - 5/30 + 70/30= 89/30=    2 29/30