170 8/51 - 2 4/9 ÷3 2/3
170 8/51-2 4/9:3 2/3=169 25/51 1)2 4/9:3 2/3=22/9:11/3=22/9*3/11=2/3 2)170 8/51-2/3=8678/51-34/51=8644/51=169 25/51
-22/9:11/3=-22/9*3/11=-2/3; 8678/51-2/3=8678/51-34/51=8644/51=169 25/51.