What is the length of the missing side of the trapezoid?

Closing a credit card usually _your debt ratio.a. increasesb. decreasesc. improvesd. has no effect on

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

My math teacher told my class to "steal" a 6th grade fraction word problem from the internet, word problems? : -p requirements: only a 1 step word problem. needs to be complex.