There are 12 inches in one foot. 120 x 12 = 1,440 inches. The correct ratio to be placed is the 5th one (aka 12 inches over 1 foot).
The Pringle’s is 2.77$ per cup and the and the frito Lays are 2.82$ per cup so the pringle’s is less cost per cup
f(x) = 5x^2 - 4x
g(x) = 5x + 1
Therefore f - g = 5x^2 - 4x - (5x + 1)
= 5x^2 - 4x - 5x -1
= 5x^2 -9x - 1
Hope it helps :)