To write raising some expression to a power, you should append '^{...}' to the expression and instead of '...' you should use a power expression, for example:

(x+y)^{2} = x^{2} + 2xy + y^{2}

In case when a power expression is a single variable or a digit the parentheses '{' and '}' can be omitted. So the last expression can be rewritten:

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

To test the mastery of the material write the following formula in TeX format: