6 3/9-(2 5/9 +7/9)=
4- 3 1/8- 5 3/8=

6 3/9-(2 5/9+7/9)=9 6/9 или 9 2/31)2 5/9+7/9=2 12/9=3 3/92)6 3/9+3 3/9=9 6/9 или 9 2/34-3 1/8-5 3/8=-4 4/8 или -4 1/21)4-3 1/8=3 8/8-3 1/8=7/82)7/8-5 3/8=-5+7/8-3/8=-5+4/8=4/8-5=4/8-4 8/8=-4+4/8-8/8=-4+4/8=-4 4/8