Answer: B. -9/2 and E. 9/2
Step-by-step explanation:
4x² - 81 = 0
Add 81 to bothside
4x² - 81 + 81 = 0+ 81
4x² = 81
Divide bothside by 4
4x²/4 = 81 /4
x² = 81/4
Take the square root of both side
√ x² = ±√81/4
x = ± 9/2
x = -9/2 or x = 9/2
x = -9/2 or 9/2
