Which relation is a function?

If a graph is a function, then any vertical line that we draw on

the graph should hit the graph at only one point.

In the image below, this looks almost identical to the fourth image you have.

I did my best to draw this one below.

Notice the red arrows I put.

Since the red arrows only hit the line at one point,

the relation must be a function so the 4th picture is your answer.

4.6875 pounds

step-by-step explanation:

a negative exponent is translated as follows:

so, we have