A linear cost model adds a one-time fee to a per-item charge. “Without exceeding” makes the budget an upper limit, so use a Desmos regression to find the count that would spend exactly the budget. That count may be a decimal, but items come in whole numbers. Choose the greatest whole number below the limit, not the nearest rounded number.
Hints
- Hint 1
A fixed fee is charged once, while a price per flyer repeats. If is the number of flyers, which charge gets multiplied by ?
- Hint 2
The budget boundary is the count that would spend exactly the available money. Find it with a Desmos regression, then ask which whole-number count stays on the affordable side.
Step-by-step
Find the budget cutoff
Step 1Write the cost limit
Let be the number of flyers. At $1.35 per flyer, the flyers cost . The $28 setup fee is paid once, so add , not . “Without exceeding” means the total can be at most $140:
- Step 2
Find where the budget runs out
The boundary is the count that would use exactly the budget:
Type in Desmos. The subscript lets Desmos fit , and tells it to match the two sides. Under PARAMETERS, it shows . Each extra flyer raises the cost, so counts above this boundary exceed the budget.
- Step 3
Check the whole numbers beside the cutoff
Flyers must come in whole numbers, so check and . Type and ; Desmos shows and . The first bill fits the $140 budget, but the next is over it. Maya’s greatest possible number is flyers. Grid in 82.