Answer: See below
Explanation:
For the problems, you need to know what makes a function, a function. In order to tell, you need to know the Vertical Line Test. The Vertical Line Test can tell you if there is only one output per input. What you do is draw vertical lines along the graph. If the line goes through the function once, then it passes the Vertical LIne Test, and is therefore a function. If the vertical line goes through 2 points, then it fails the test, which makes it not a function.
1. Not a function
We have defined that a function only has one output for one input. In the table, we see that x=7 has 2 outputs, y=10 and y=3. This does not pass the Vertical Line Test because if you drew a line at x=7, it will go through 2 points.
2. Function
On this graph, if you draw many vertical lines, you will see that wach line only passes the function once. Therefore, this is a function.