Solve for the value of c

Data are collected to see how many ice-cream cones are sold at a ballpark in a week. day 1 is sunday and day 7 is the following saturday. use the data from the table to create a scatter plot.

The final cost of a sale is determined by multiplying the price on the tag by 75%. which best describes the function that represents the situation?

Determine the area of a triangle with (see picture below)