Question

I really need help with question numbers 7 and 8.

Answer 1

Given:

The graph represents the number of t shirts and its cost.

The objective is,

i) To find the rate of change of the graph.

ii) To explain the coordinates (0,0) and (1,9).

Step-by-step explanation:

i)

The coordinates in the graph are (0,0), (1,9), (2,18), (3,27).

The general formula to find the rate of change is,

`\Delta r=(y_2-y_1)/(x_2-x_1)`

On plugging the coordinates in the above equation,

`\begin{gathered} \Delta r=(9-0)/(1-0)=(9)/(1) \\ \Delta r=(18-9)/(2-1)=(9)/(1) \\ \Delta r=(27-18)/(3-2)=(9)/(1) \end{gathered}`

Hence, the rate of change for the graph is 9.

ii)

In the graph the data in x-axis represents the number of T-shirts and the data in y-axis represents the cost of T-shirt.

So, the coordinate (0,0) represents that the cost of zero T-shirt is $0.

Similarly the coordinate (1,9) represents that the cost of one T-shirt is $9.

Hence, the cost of each T-shirt is $9.