3 целых 2/3-7/15+4 целых 2/5*1/3
3(2/3)-(7/15)+4(2/5)*(1/3)=4(2/3).
1) 4(2/5)*(1/3)=(22/5)*(1/3)=(22/15);
2) 3(2/3)-(7/15)=(11/3)-(7/15)=(55-7)/15=48/15;
3) (48/15)+(22/15)=(48+22)/15=70/15=4(10/15)=4(2/3).