Simplify (-xy)^2

${(- x y)}^{2}$

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

Apply the product rule to $- x y$ .

${(- x)}^{2} y^{2}$

Apply the product rule to $- x$ .

${(- 1)}^{2} x^{2} y^{2}$

Raise $- 1$ to the power of $2$ .

$1 x^{2} y^{2}$

Multiply $x^{2}$ by $1$ .

$x^{2} y^{2}$