va rog ajutati-ma rapid e urgent

Explicație pas cu pas:
d) 7/15+1/5=2/3
2/3×3=6/3=2
e) 3/7-1/21=8/21
8/21×14=16/3=5 1/3
f) 1-1/9=8/9
8/9×3=8/3= 2 2/3