Răspuns:
4/7 ×5/2=2/7×5/1=10/7
28/9×15/7=4/9×15/1=4/3×5/1=20/3
4/7:8/9=4/7×9/8=1/2×9/7=9/14
32/9:8/3=32/9×3/8=32/8×3/9=4×1/3=4/3