Well without seeing the tables it is hard to answer. However, I will offer some help. f(x) is actually y. A function of x=y. So, now you have y=2x-1. Plug the x and y values in from the tables and make sure the equations are true with the given values (equal on both sides). For example, (2,3).. 3=2(2)-1...... 3=3. Hope this helps.