Since a(12) = 35, Hillary will have 35 dollars remaining on her card after purchasing 12 apps.
Step-by-step explanation:
- The given equation is a(x) = 50 - 1.25x, where x is the number of apps purchased and a(x) is the amount of money remaining on Hillary's gift card after buying x apps.
- So we substitute x = 12 in the equation to solve for a(x). a(12) = 50 - (1.25 × 12) = 50 - 15 = 35.
- From this, we understand that Hillary's card was worth 50 dollars but after buying 12 apps which cost 1.25 dollars each she has a remaining of 35 dollars on her card.