Пошаговое объяснение:
2/5*(3 1/3+5 1/6) +2 3/4:(1 1/2- 2/5)=
=3 2/6 +5 1/6=8 1/2
=1 5/10-4/10=1 1/10
=2/5*8 1/2=2/5*17/2
=3 2/5
2 3/4:1 1/10=11/4* 1/11=1/4
=3 2/5+1/4=3 8/20+5/20=3 13/20
