The base pay of a water-delivery person can be described as
f(x)=210 + 0.2x, where f(x) is the total
earnings and x is the number of items
sold. What is the difference in total
earnings between selling 110 items
and 130 items?

Jack has a rectangular piece of land, the area of which is represented by a1 = 9.5l. his brother has a different rectangular piece of land, the area of which is represented by a2 = l(14 − l). let a represent the area in square meters and l represent the length in meters of the pieces of land. the two equations plotted on a graph meet at a point as shown in the image