If f (x) = 2x+12 how much to rent 7 movies. She has $10 how much more does she need

Assuming x = total amount of movies, plug 7 into the equation.

2 (7) + 12

14 + 12 = 26

It costs $26 to rent 7 movies.

Subtract the total cost by the amount she has to find how much more money she needs.

26 - 10 = 16

She needs $16 more to rent the 7 movies.

She has to have 16 more dollars. because the movies cost 26 dollars.