Răspuns:
Explicație pas cu pas:
a) 2/7+1/7=3/7 scrie in primul cerc
3/7+4/7=1 scrie in al doilea
1-3/5= 2/5 scrie in al 3 lea cerc
2/5+1/5=3/5 scrie in ultimul cerc de la a)
b)
3/11+6/11=9/11
9/11-9/11=0
0+5/6=5/6
5/6-2/6=3/6=1/2
c)
3/28:1/7=3/28·7=3/4
3/4·5/6=15/24=5/8
5/8:15/16=5/8·16/15=2/3
2/3·9/10=3/5
