1 целая 2/3*3-3/8*(1цел 1/3+2 цел 2/9):2=
=5-3/8*(4/3+20/9):2=5-3/8*(12/9+20/9):2=5-(3*32*1)/(8*9*2)=5-2/3=15/3-2/3=13/3