Evaluate the following double integral over the region R by converting it to an iterated integral. ∬ (x + 6y) dA; R = {(x, y) : 1 ≤ x ≤ 3, 2 ≤ y ≤ 4} Choose the two integrals that are equivalent to ∬ (x + 6y) dA. (x + 6y) dx dy (x + 6y) dy dx (x + 6y) dy dx (x + 6y) dx dy Evaluate the integral. ∬ (x + 6y) dA = (Type an exact answer.)