So what you would do is make a table and put X on the top left side, and Y on the top right side. Put a zero on both sides. The firs one on the top left under X, and the second one on the bottom on the bottom right. Now, what you do is you take 7x=16, and divide 7 from both sides. Of course the answer is going to be a decimal. Now; you do the same thing again. Only with the 4y. And the answer is 4. Hope it I clear enough for you!!!1 ;)