Answer:
- $70
- y = 25 + 0.9x
- $250
Step-by-step explanation:
1. 10% of $50 is $5, so the purchases would come to $50 -5 = $45. Added to the $25 membership fee, the total cost for the year would be
$45 +25 = $70
2. The member pays $25 even if no purchases are made. Then any purchases are 100% - 10% = 90% of the marked price. So, the total is ...
y = 25 + 0.90x
3. $25 is 10% of $250, so that is the amount the member would have to purchase to break even on cost.
If you like, you can compare the cost without the membership (x) to the cost with the membership (25+.9x) and see where those costs are equal.
x = 25 +0.9x . . . . . x is the spending level at which there is no advantage
0.1x = 25 . . . . . . . . subtract 0.9x
25/0.1 = x = 250 . . . divide by 0.1
