The answer is X.
In order for it to be a function, there should be only one y-value for every x-value. Graph x is the only one that obeys this rule, therefore it is the answer
Answer:

Step-by-step explanation:
The equation of a line is usually written in the form of y=mx+c, where m is the gradient and c is the y-intercept.
The product of the gradients of perpendicular lines is -1.
Gradient of given line= 3.
(Gradient of line)(3)= -1
3m= -1
m= 
subst. m=
into the equation:

To find the value of c, substitute a coordinate.
When x=0, y=4,

Thus the equation of the line is
.
THE FIRST ONE AND THE LAST ONE