Which property is used below 4xy^2 =8y^2 and 8y^2=72, then 4xy^2=72. a)reflexive property. b) substitution property. c) symmetric property. d) transitive property

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