To find this, we can begin by looking at the steps to solve this problem. We know that this involved the 'opposite' and 'adjacent' sides, meaning we must use 'cos' in this instance.
We can set up an equation like this:
cos73°= .
We can simply rearrange this to form a possible answer choice:
y·cos73°= x.
This is one of the answer choices! That is your final answer.