Question

When Jack went to the movie he paid $8 for his popcorn and $4 for each additional order of popcorn. If y represents the total cost and x represents the number of popcorn orders, what is the function rule that describes this pattern?

A. y = 4(x – 1) + 8
B. y = 4(x – 1) – 8
C. y = –4(x + 1) + 8
D. y = –4(x + 1) – 8

Answer 1

4x-x+8
4(x-1)+8
A. y=4(x-1)+8

Answer 2

A. y = 4(x – 1) + 8

Explanation:

Considering the statement, the total cost can be calculated by adding 8 that is the price for the first order of popcorn plus the number of additional orders multiply by 4 that is the price of each of these orders.

Then, the number of additional orders would be equal to x that represents the number of popcorn orders minus 1 as the first order should not included because it has a different price. According to this, the function rule that describes this pattern is:

y= 4(x-1)+8