There is a type of question, the square of (x + y) = 25, the square of (X-Y) = 9 There is a type of problem, the square of (x + y) = 25, the square of (X-Y) = 9, the value of multiplying X by Y and the square of X + y. how to do this type of problem? I know the answer. I want to know the solution to this type of problem,

There is a type of question, the square of (x + y) = 25, the square of (X-Y) = 9 There is a type of problem, the square of (x + y) = 25, the square of (X-Y) = 9, the value of multiplying X by Y and the square of X + y. how to do this type of problem? I know the answer. I want to know the solution to this type of problem,

(x + y) ^ 2 = x ^ 2 + 2XY + y ^ 2 = value
(X-Y) ^ 2 = x ^ 2-2xy + y ^ 2 = value
Add to get the value of x ^ 2 + y ^ 2
Then subtract the value of x ^ 2 + y ^ 2 from the value of x ^ 2 + 2XY + y ^ 2 to get the value of XY