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Question

Which of the following is not a solution to the equation 9h³=h ?

A. 0

B. 3

C. 1/3

D. -1/3

Answer 1

Beatriz, let's plug in each answer and see.

 

9(0³) = 0

9(0) = 0

0 = 0

True

 

9(3³) = 3

9(81) = 3

729 = 3

False

 

9(1/3)³ = 1/3

9(1/27) = 1/3

9/27 = 1/3

1/3 = 1/3

True

 

9(-1/3)³ = -1/3

9(-1/27) = -1/3

-9/27 = -1/3

-1/3 = -1/3

True

 

Looks like the answer is B.

 

Hope this helps!

Answer 2

You can solve the equation by factoring:

 

9h³ = h

 

9h³ - h = 0

 

h(9h² - 1) = 0

 

h(3h - 1)(3h + 1) = 0

 

Set each factor equal to zero and get h = 0, 1/3, -1/3

 

So, of the four choices, the only one that doesn't work is B.