in this question, each package has 8 notecards.
one notecard costs $8
2 notecards cost $16
3 notecards cost $24
if n - number of packages
d - selling price in dollars
We can see that with each additional notecard bought the cost increases by $8
therefore there's a proportional relationship between n and d
As n increases, d increases by the same amount.
if we put it in an equation,
d = 8*n
n - 1 package and d is 8
if n - 2
d = 8*2
d = 16
Therefore we can use the following equation;
d=8n
