Answer:
One possible answer could be 0.8x.
Explanation:
Think of it this way, if a store took 20% off a price, how much would be left?
Well, that's fairly easy to solve.
100% - 20% = 80%
(100%) - (discount %) = amount you need in a equation.
Now that you have 80%, convert it to a decimal.
80% ---> 0.8
Considering that x, would be the normal store price, how can you use 0.8 in the equation?
Well, simple, just multiply x by 0.8.
x * 0.8 = the discount
All there's left to do is to simplify it some more.
x * 0.8 ---> 0.8x
That's All!
***Please note:
Because you listed it as which expressions could be the answer and did not list the choices, I only provided a sample answer. If you can provide more details, I'll be glad to help.