Substitute the variable terms with the coordinates and the equation is
3=1/3(5)+b
solve for b
Nellie has to calculate the price per pound for every bag.
1) 2.52 / 3.5 = 0.72 $/lb
2) 5.40/7.5 = 0.72 $/lb
3) 7.92/11 = 0.72 $/lb
Then, price per pound is the same for any bag. There is no advantage of purchasing one or other, given that she can store any quantity.
