Question 135067
The domain is the set of all valid value for the 'independent' variable. The range is the set of the resulting 'dependent' variable.

So, let's say you had a function like {{{y = 5 + 2x}}}
Then the domain is the set of all valid values for x and the range is the values you would get for all the 'y' when you subbed in all the 'x's.

As far a a function goes, let's say you want to go to a local theme park. Tickets  are $25 and parking is $10.

The total price for a family is given by {{{P = 25a + 10}}} where a is the number of people in the family.

For that function the domain is all values of 'a' that are positive (no family has 0 or negative number of members).

The range is (35, 60, 85, 110, etc... like that)