help me, will mark brainlist

Hello from MrBillDoesMath!
Answer:
"The factoring should follow the perfect square trinomial pattern"
Discussion:
y^2 - 2(y)(3) + 3^2 =
(y -3 ) ^2
not (y-3) (y+3) so the last step shown is incorrect. The answer is "The factoring should follow the perfect square trinomial pattern"
Thank you,
MrB