x≥3
Y represents the number of pets in Joel's family and x represents the number of pets in Brian's family. Because we know that y=4+x, and that the combined number has to equal 7 or greater, we subtract 7-4=3. There for the minimum value for x is three. In the question, it states "at least 7 pets" so we know that both x/y may equal more than 7. So we use a ≥ sign to show that the number of pets in Brian's family may be three, or more.
