Answer
$3$.
Work Step by Step
The given expression is
$=\sqrt{x^2}+\sqrt{y^2}$
Substitute $x=2$ and $y=-1$.
$=\sqrt{(2)^2}+\sqrt{(-1)^2}$
Use the law of exponents $(a)^n=a^{ n}$.
$=\sqrt{2^2}+\sqrt{1^2}$
The principal square root is nonnegative.
The absolute value is
$=2+1$
Simplify.
$=3$.
