3 5 4 5 54 6
(2---+1--- ) - (1---+ ---)= (17/7+14/9)-(11/7+5/9)=(153+98-99-35)/63= 117/63=1 = 1---
7 9 7 9 63 7
3 5 4 5 54 6
(2---+1--- ) - (1---+ ---)= (17/7+14/9)-(11/7+5/9)=(153+98-99-35)/63= 117/63=1 = 1---
7 9 7 9 63 7