Given the line on the graph, we have that it passes through the points (1,25) and (2,50), then we can find the relation function with the slope-point equation of the line:
[tex]\begin{gathered} \text{slope:} \\ m=\frac{y_2-y_1}{x_2-x_1} \\ \Rightarrow m=\frac{50-25}{2-1}=\frac{25}{1}=25 \\ y-y_1=m(x-x_1) \\ \Rightarrow y-25=25(x-1) \\ \Rightarrow y=25x-25+25=25x \\ y=25x \end{gathered}[/tex]
we have that the cost of the dirt is given by the equation y=25. To find how much would it be for 40 cubic yards of dirt, we make x=40 and we get the following:
[tex]\begin{gathered} x=40 \\ \Rightarrow y=25\cdot40=1000 \\ y=1000 \end{gathered}[/tex]
therefore, the cost to haul 40 cubic yards of dirt is $1000
