this is true because to be a function every value of x can only have one y value and all of the pictures have an x value that has more than one y value except for that last one
Ok so first, write down the equation. We know that x=3 and y=4. You just basically plug in the terms into the variables. So it would be 3(3)+1/4(4)^2. Simplify that equation and you should get your answer :)
