How do we know that the amount of contaminated soil remaining is a linear function of the number of days worked? The amount of contaminated soil remaining decreases at a constant rate based on the number of days worked, so the function is linear. As the number of days worked increases the amount of contaminated soil remaining decreases, so the function is linear As the amount of contaminated soil decreases the number of work days increases, so the function is linear. The number of days worked is always greater than or equal to zero, so the function is linear. The amount of contaminated soil remaining is always greater than zero, so the function is linear. Part 2 State the formula for the amount of contaminated soil remaining, R, as a linear function of the number of days worked, n. Use the formula to determine the amount of contaminated soil remaining after 31 days of work. Submit Answer