1) (3,5+2 1/3)/(3,5-2 1/3)=(35/10+7/3)/(35/10-7/3)=(105/30+70/30)/(105/30-70/30) =175/30÷35/30=175/30×30/35=5
2) (16-8 1/3)/(-2 5/9)=(48/3-25/3)/(-23/9)=23/3÷(-23/9)=23/3×(-9/23)= -3
3)-10 8/61-12.5×(-2/9)2= -618/61+125/45×2= -618/61+25/9×2= -618/61+50/9=
-5562/549+3050/549= -2512/549= -4 316/549