Out of the four trinomials, y^2+18y+81 is correct.
Step By Step Answer:
To determine a perfect square trinomial, the first and third terms have to be square roots and the middle term has to be two times the square root of the third term.
y^2 is a square root and 81 is a square root.
y^2 simplifies to y and 81 simplifies to 9.
It would be y+18y+9
The third term is 9, so multiply that by two and you get 18!
Therefore, that is correct!
y^2+18y+81 is a perfect square trinomial!
Hope this helps!
