Question 189314
The square of the sum of two numbers equals the sum of their squares plus twice their product.


This should be obvious as it is applied to all values – it doesn’t have any specific solutions.


The square of the sum of two numbers: (x + y)^2; equals the sum of their squares plus twice their product: x^2 + y^2 + 2xy.


Well, (x + y)^2 = x^2 + y^2 + 2xy for all values of x and y, so it is like saying two times the number equals the number times two, which applies to all numbers.


So the question is nothing more than a statement of what expanding the expression (x + y) to the second power gives.