Răspuns:
Explicație pas cu pas:
a). 4/15*1 3/7=4/15*10/7=4/3*2/7=8/21
b). 2 2/5*1 7/18=12/5*25/18=2/1*5/3=10/3
c). 2 7/9*1 7/20=25/9*27/20=5/1*3/4=15/4
d). 3 8/9*4 4/25=35/9*54/25=7/1*6/5=42/5
e). 1 5/7* 4 5/18=12/7*77/18=2/1*11/3=22/3
f). 4 1/5*3 3/14=21/5*45/14=3/1*9/2=27/2
