Question

The graph below represents the amount of change Jaxon would receive, y, if he bought a item with a cost of x.


Which equation represents the graph?
y = 10 – x
y = x – 10
y = –x – 10
y = 10 + x

Answer 1

The line crosses the y axis at positive 10
The line is going down when you go from left to right so there must be a - before the x

The answer is A

Answer 2

Answer:  The correct option is (A) $y=10-x.$

Step-by-step explanation:  The given graph represents the amount of change Jaxon would receive 'y' if he bought a item with a cost of 'x'.

We are to select the correct equation that represents the graph.

We notice from the graph that it is a straight line and the points (0,10) and (10, 0) lies on the line.

The slope of a straight line passing through the points (a, b) and (c, d) is given by

$m=\dfrac{d-b}{c-a}.$  

So, the slope of the given line is

$m=\dfrac{0-10}{10-0}\\\\\\\Rightarrow m=-1.$

Since the line passes through the point (10, 0), therefore the equation of the line representing the graph is

$y-10=m(x-0)\\\\\Rightarrow y-10=-1(x-0)\\\\\Rightarrow y-10=-x\\\\\Rightarrow y=10-x.$

Thus, the required equation is $y=10-x.$

Option (A) is CORRECT.