Answer:
Option 1,2 and 5 represent a perfect square monomial and its square root.
Explanation:
To find : Which expressions represent a perfect square monomial and its square root? Check all that apply.
Solution :
1) 121, 11
As

This expression represents a perfect square monomial and it’s square root.
2)

As

This expression represents a perfect square monomial and it’s square root.
3)

As

This expression does not represents a perfect square monomial and it’s square root.
4)

As

This expression does not represents a perfect square monomial and it’s square root.
5)

As

This expression represents a perfect square monomial and it’s square root.
Therefore, Option 1,2 and 5 represent a perfect square monomial and its square root.