Help please!
Find f(-4)=

Mozart lenses inc. recently introduced seelites, a thinner lens for eyelasses. of a sample of 800 eyeglass wearers, 246 said they would purchases their next pair of eyeglasses with the new lenses. lenses inc. estimates that the number of people who purchase eyeglasses in a year is 1,700,000. most eyeglasses wearer buy one new pair of eyeglasses a year. what is the annual sales potential for the new lenses.

Ihave trouble finding the nth term of a linear sequence

The sum of these consecutive integers is equal to 9 less than 4 times the least of the integer. find the three integers