Question 1104211
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Recall that dividing by zero is undefined, so it is not allowed.


Set the denominator equal to zero, factor and use the zero product property to find the x values that solve the equation


x^2 - 81 = 0
x^2 - 9^2 = 0
(x-9)(x+9) = 0
x-9 = 0 or x+9 = 0
x = 9 or x = -9


The two x values not in the domain are x = 9 and x = -9. These x values make the denominator x^2-81 equal to zero.
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