inverse means 1 over the other so y=1/x, we are given that y=2 when x=5 so our equation turns into 2=/=1/5, these things do not equal so we have to add a coefficient to the right to make this statement true. I would select 10, so that it becomes y=10/x, when the values are plugged in it becomes 2=10/5 or 2=2.