(4 целых 10/21 + 2 целых 1/3) + (3 целых 3/5 + 1 целая 1/2)
136.
59+23+37=59+(23+37)=59+60=119
85+39+15=(85+15)+39= 100+39=139
137.
17+22+23+28=(17+23)+(22+28)= 30+40=70
34+91+19+36=(36+34)+(91+19)=70+110=180
138.
а+70+b=(a+b)+70=15+70=85
7+a+33+b=(a+b)+(7+33)=15+40=55
4-1 1/3=4-4/3=4/1-4/3=12-4/3=8/3=2 2/3