Which table of values dose not represent a linear function

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Kendra had twice as much money as kareem. kendra later spent $8 and kareem earned $6. by then,the two had the same amount of money. how much money did each have originally?

How many solutions does the nonlinear system of equations graphed below have? a. one b. zero c. four d. two