What are the restrictions on the variable 1/9x-1

 The restriction is:  
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             " x  " .
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Given:
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" " ;   The "denominator" cannot be "0";  because we                                                             cannot divide by "0" .
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So the restriction(s) on the variable, "x", is that "x" cannot be equal to the value at which the "denominator would equal zero" .

So, set the "denominator" equal to "0" ; and solve for "x" .

9x – 1 = 0 . 

Add "1" to each side of the equation:

9x – 1 + 1 = 0 + 1 ; 

9x = 1 ; 

Divide each side of the equation by "9" ; 

9x / 9 = 1/9 ; 

   x =  .
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So, the restriction is:
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" x " .
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