Answer:
15:x or 15 to x
Step-by-step explanation:
it depends on what the question is asking, so if they want you to fill in a number, you could replace x with any number you'd like. but its probably a word problem they want you to put as numbers, so bc you dont know what 'a number' is, you can pick a variable such as x to replace it with.
hope this helps :)
