4 5/9+(13 2/7-6 5/13)+4 2/9-(1 1/3-2/3) = 4 5/9 + (13 26/91 - 6 35/91)+ 4 2/9 -
- (4/3 - 2/3)= 4 5/9 + (12 117/91 - 6 35/91) + 4 2/9 - 2/3= 4 5/9 + 6 82/91 + 4 2/9 - 6/9 = 4 182/819 + 6 738/819 + 3 11/9 - 6/9 = 10 920/819 + 3 5/9 = 11 101/819 + 3 5/9 = 101/819 + 3 455/819 = 3 556/819