Do you have the answer options?
All you have to do is look at the key words.
15 cents to print each copy of a poster meaning 15 cents times each copy of a poster. Each copy of poster would be a variable.
Plus a flat tee of $4.95 per order meaning you would add 15 cents times each copy of a poster plus 4.95 per order. Per order would also be a variable.
Example:
.15(variable/each copy of a poster) + 4.95(variable/per order)
I hoped this helped a little.