5/9+1 5/7*(4 2/3-2 5/8):1 3/4=
= 5/9+1 5/7*2 1/24:1 3/4=
=5/9+12/7*49/24*4/7=
=5/9+2=2 5/9
,2-3 1/7*(2-1 9/11):8/21=
=2-22/7*2/11*21/8=
=2-1 1/2=1/2
2 1/3+4 1/10:(2 7/15-5/12)*5/6=
=2 1/3+41/10*60/123*5/6=2 1/3+5/3=2 6/3=4
4 5/12-1 1/2:(2 1/6+8/15)*1 4/5=
=4 5/12-3/2*30/84 *9/5=
=4 5/12-1 =3 5/12
=