Question

Which of the following situations is represented by the graph below

Answer 1

The given graph represents the relationship between the number of lemonade glasses that Brian sold (x-axis) and his earnings (y-axis)

The y-intercept, i.e. the point where the line crosses the y-axis, indicates the initial value of his earnings.

This value is y= -$80, the fact that the earnings are negative, indicates that to start he had to spend $80 to set up the lemonade stand.

The slope of the line indicates the price of each glass of lemonade, to determine its value you have to choose any two points of the line and calculate the slope using the following formula:

`m=(y_2-y_1)/(x_2-x_1)`

Where (x₁,y₁) and (x₂,y₂) represent the coordinates of both points.

You can use, for example, the intercepts:

y-intercept (0,-80) → (x₁,y₁)

x-intercept (400,0) → (x₂,y₂)

`\begin{gathered} m=(0-(-80))/(400-0) \\ m=(80)/(400) \\ m=0.20 \end{gathered}`

The slope is $0.20/lemonade glass

This means that he earned $0.20 per lemonade glass sold.

The correct option is the third one.