Well, a linear function is proportional, a straight line (on a graph). And the numbers must not have the same answer. For instance, if the X input is 5, and the Y output is 7. And then another X input is 5, and the Y output is 8, that's non-linear.
So, the Answer would be the third graph. This is because the X values are steadily increasing, and so are the Y values.
For the X and Y values, for each time X increases by 1, Y increases by -8. This is, linear because both sides are constantly and evenly increasing.
ANSWER
a relation only
EXPLANATION
The given graph shown in the attachment represents only a relation and not a function.
The reason is that, a vertical line drawn across this graph will intersect this graph at more than one point.
Since the graph fails to pass the vertical line test, the ordered pair represented by this graph represents a relation only.
253 * 0.27= 68.31 (discounted price)
253-68.31 OR 253*0.73= 184.69 (sale price)