Test 3 Section 4 #30

This one is yucky. Let’s attack it by substituting. First, we’re told that , so let’s reflect that (I’m going to use the decimal version of for simplicity):

   

Now, let’s solve both equations for c:

   

Because we now have two different equations with c isolated, we can substitute again here to get an equation that only contains xs and ys.

   

That translates to “x is y minus ,” so the answer is A.