1 1/3*(8 2/3 : 1 4/9 - 3 3/8 + 1 5/8) - 1 5/6 = 3 5/6
8 2/3÷1 4/9=26/3÷13/9=26/3×9/13=6 3 3/8+1 5/8=4 8/8=5 6-5=1 1 1/3×1=1 1/3 1 1/3-1 5/6=4/3-11/6=8/6-11/6=-3/6=-1/2
спасибо большое