Let \iint_{[a,b]\times[c,d]} f(x, y)dA denotes the integral of f(x, y) over the region with
a \le x \le b and c \le y \le d. Find \iint_{[2,3]\times[0,1]} f(x, y)dA given the following:
$\iint_{[0,1]\times[0,2]} f(x, y)dA = 4$,
$\iint_{[0,2]\times[0,1]} f(x, y)dA = -2$,
$\iint_{[0,3]\times[1,2]} f(x, y)dA = 3$,
$\iint_{[1,3]\times[0,2]} f(x, y)dA = 7$.