4 1/3 + 2/3 : 5 - 3 4/5
8 1/2 - 3 1/2 : (2 1/2 + 1 3/4) * 2 3/7
4 1/6 + ( 2 3/4 - 2 /1/6) : 2 4/5 - 1 3/8
1 4/21 : 5/7 - 2/5 * 5/7
( 3 5/6 - 2 3/4) : 7/12 + 5 1/2=(23/6 - 11/4)*12/7 + 11/2=(46/12 - 33/12)*12/7 + 11/2=(46 - 33)/12 * 12/7 + 11/2=13/7 +11/2=26/14 + 77/14=(26+77)/14=103/14=7 5/4
9 - 3 1/5 * 1 2/3 + 1 1/3=9- 16/5 * 5/3 + 4/3 =9 -16/3 + 4/3= 9 - 12/3=9 - 4=5
21 : 2 1/3 - ( 1 3/4 + 2 4/5 )= 21 : 7/3 - (7/4 +14/5) = 21*3/7 - (35/20 + 56/20) =9 - (35+56)/20=9 - 91/20=(180-91)/20=89/20= 4 9/20
3 1/5 * ( 1 5/12 + 7/8 ) : 11/13=16/5 * (17/12 + 7/8)=16/5 * (34/24 + 21/24)=16/5 * (34+21)/24=16/5*55/24=(4*11)/6=(2*11)/3=22/3=7 1/3