The problem is to expand the expression $(x-y)^2$.

1. Problem Description

The problem is to expand the expression $(x-y)^2$.

2. Solution Steps

We need to expand $(x-y)^2$. This is a binomial squared. We can use the formula:

$(a-b)^2 = a^2 - 2ab + b^2$

Applying this formula to $(x-y)^2$ where $a=x$ and $b=y$, we get:

$(x-y)^2 = x^2 - 2(x)(y) + y^2$

$(x-y)^2 = x^2 - 2xy + y^2$

3. Final Answer

$x^2 - 2xy + y^2$