Answer :
ANSWER:
$7.5 per box
STEP-BY-STEP EXPLANATION:
We must calculate the slope of the line to know the price of each card:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]Replacing the points (0, 0) and (4, 30):
[tex]m=\frac{30-0}{4-0}=\frac{30}{4}=7.5[/tex]Which means that the cost per box is $7.5