Let R be the region of the plane bounded by the curves: y = 2x, y = 2(4 - x); y = 3x, y = 3(4 -x). 1) Calculate the area of R by means of an integration in x and y. 2) Consider the coordinates s and t defined by S = 8 10 t = 4 - 20 3) Calculate the Jacobian determinant for the change from x and y to s and t. 4) Calculate the area of R again by means of an integration in s and t