9. Which is a possible value of n to make 8xn - 64 a difference of two cubes? A. 3 B. 8 C. 15 D. 25 10. What will you multiply to (3x + y) to make a perfect square trinomial? A. 3x + y B. - y + 3x C. 3x - y D. 3x² - y2 11. Which of the following is a difference of two squares? A. ײ+4 B. ×⁴y3 - 100 C. 2x² - 9 D. 4x⁸y² - 49