Can You Name 2 Fact Families That Have Only Two Equations?

The example of two fact families can be the two equations, which are as follows:

1 + 1 = 2

2 - 1 = 1

The above mentioned are the two fact families because there are only two numbers 1 and 2 are used to make the complete equation. Similarly the three fact families are like:

3 x 5 = 15

5 x 3 = 15

15 ÷   3 = 5

15 ÷   5 = 3

I hope you get an idea now!