Answer:
f(x) = 1.38x
x just stands for a number so depending on how many pounds you get you would times the pounds by 1.38. And f(x) (pronounced "f of x") means that each input has a single output. So if you bought 2 pounds of strawberries, the equation would change to this:
f(2) = 1.38(2)
The x's were just replaced with 2's, see? I wish someone had explained this to me earlier lol
