Let R be the region of the plane bounded by the curves: y = 5x, y = 5(2 - 2); y = 3x, y = 3(2 - 2). 1) Calculate the area of R by means of an integration in x and y. 2) Consider the coordinates s and t defined by y S = t = 2 -X 3) Calculate the Jacobian determinant for the change from a and y to s and t. 4) Calculate the area of R again by means of an integration in s and t