1)3/7×a=1
2)8/9:p=2/3

1) a = 7\3
2) 8\9 : p = 2\3
8\9 · 1\p = 2\3
8\9p = 2\3
24 = 18p
18p = 24
p = 4\3 

3/7а = 1
а = 7/3
3/7 • 7/3 = 1
1 = 1

8/9 : p = 2/3
8/9 : p = 2/3
8/9 • 1/p = 2/3
8/9p = 2/3
24 = 18p
18p = 24
p = 4/3

@iGeniusOX⚡