Multiple choice What is (9x + 10) (9x - 10) in expanded form? 81x2 + 100 100x2 - 81 81x2 - 100 9x2 - 10 Reveal answer Fill a bubble to check yourself C Correct answer Explanation (9x + 10) (9x - 10) = 81x2 - 90 + 90x - 100 (Using Foil) = 81x2 - 100