(1 point) In this problem we use the change of variables x = 4s + t, y = s - t to compute the integral p(x + y) d A, where R is the parallelogram with vertices (x, y) = (0, 0), (4, 1), (6, -1), and (2, -2). First find the magnitude of the Jacobian, o(x, y) = a(s, t ) Then, with a = 0 b = C= 0 , and d = JR(x + y) dA = Sa Sa S+ ) dt ds =