If you are looking for the intersect between the two lines, the answer is (1, 9)
<span>A+B)^2 is the largest. It is A^2+2AB+B^2, which is clearly greater than the last two options. To compare (A+B)^2 and 2(A+B), we remove one A+B so that we're just comparing A+B and 2. As A+B must be at least 3 (as both must be positive integers, and one must be greater than the other, leading to a minimum value of A=2, B=1), A+B is greater than 2, and as a result, (A+B)^2 is always the largest.</span>
There are no real solutions