Dylan opened a credit card account with $600.00 of available credit. Now that he has made some purchases, Dylan's account only has $390.00 of available credit. What is the percentage decrease of the amount of available credit in Dylan's account?

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