Need this asap i need to find out which is a function but i get really confused on these things

Step-by-step explanation:

Use the "vertical line test."  Draw a vertical line through each graph.  If the line intersects the graph in more than one place, the graph does NOT represent a function.  Only the graph in the upper, right-hand corner represents a function, as a vertical line intersects this graph in only one place.

b. would be the answer : )

step-by-step explanation:

step 1: add -16x to both sides.

16x−4y+−16x=64+−16x  

−4y=−16x+64

step 2: divide both sides by -4.

−4y /-4 = -16x + 64/-4

answer:   y=4x−16

hope i'm right