Hiking up a mountain, you notice that the air temperature drops 10°c for every 1,000 meters increase in elevation to represent the decrease in temperature if you hike up the mountain 2,000 meters. then evaluate the expression and explain it's meaning

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