Answer:
(1 -2y)(1 +2y)
Step-by-step explanation:
The difference of squares is factored as ...
... a² - b² = (a -b)(a +b) . . . . . . . . a form you should keep handy
Here, you have a=1, b=2y, so your factored form is ...
... 1 -4y² = (1 -2y)(1 +2y)
