Hi there!
Here are all the steps into multiplying these 2 parentheses :
(9x + 2y) × (9x - 2y)
9x × 9x = 81x²
9x × -2y = -18xy
2y × 9x = 18xy
2y × -2y = -4y²
81x² - 18xy + 18xy - 4y²
-18xy + 18xy = 0
Your answer is: 81x² - 4y²
There you go! I really hope this helped, if there's anything just let me know! :)
