What is the missing number in the following equation? 11/15 - ?/6 = 6/15

You first subtract both sides by (11/15) and you get (-x/6) = (5/15). Then you multiply both sides by (-6). You're left with (x=30/15). This of course can be simplified to (2). Your answer is (x=2)

Then you check it to make sure your answer is correct by plugging (2) into x.