Since you did not provide options for what 80

x could be equivalent to,, it is near to impossible to answer this question fully. I will simplify 80

x for you and then when you can provide the options for me,, I could help you find the answer if you need it.
To simplify this you must reduce the numbers with 4 in order to find your final answer.
20x.
This means that the correct answer to your question is 20x.
Let me know if you have any further questions.
:)