Answer:
40n
Step-by-step explanation:
(40+n): The first one is asking to add forty and n, however the question is asking for multiplication so that is not an answer.
(n-40): This one is using subtraction, so this one is an obvious no.
(40/n): This phrase represents division, this could be a possibility because it is the inverse operation, however the numbers need to be reversed.
(40n): Im thinking that you got confused because there was no operation symbol. Whenever a number and a variable are attached without an operation symbol in between, you multiply. So, this is the correct answer.