9 4/7*9 4/7=
9 3/7*9 3/7=
21 7/12*21 7/12=
2 5/12*2 5/12=

Пошаговое объяснение:

9 4/7 ·9 4/7=67/7 ·67/7=4489/49=91 30/49

9 3/7 ·9 3/7=66/7 ·66/7=4356/49=88 44/49

21 7/12 ·21 7/12=259/12 ·259/12=67081/144=465 121/144

2 5/12 ·2 5/12=29/12 ·29/12=841/144=5 121/144