Question

Which of the following are solutions to the equation below? Check all that apply. 9x^2-64=0

A. 8
B. -8
C. -3/8
D. 3/8
E. -8/3
F. 8/3

Answer 1

E. -8/3

F. 8/3

Explanation:

9x^2-64=0

Add 64 to each side

9x^2-64+64 = 0+64

9x^2 =64

Divide each side by 9

9x^2/9 = 64/9

x^2 = 64/9

Take the square root of each side

sqrt(x^2) = ±sqrt(64/9)

We know that sqrt(a/b) = sqrt(a)/sqrt(b)

x = ±sqrt(64)/sqrt(9)

x = ± 8/3