oblicz
3/4 * 4/3 =
7/10 * 10/7 =
16/21 * 21/16 =
11/6 * 6/11 =
2/33 * 33/2 =
uzupełnij
2/5 * x/x = 1
9/10 * x/x = 1
3/7 * x/x = 1
x/x * 7/13 = 1
x/x * 18/19 = 1