Answer:
n = 2
Step-by-step explanation:
In order for the ratio to have a value of 1, the sum of exponents in the numerator must equal the sum of exponents in the denominator:
n + 7 = 9
n = 9 -7 . . . . . . subtract 7 from both sides of the equation
n = 2
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Alternatively, you can simplify the given expression:
[tex]\dfrac{9^n(9^7)}{9^9}=1=\dfrac{9^n}{9^2}[/tex]
Hopefully, it is clear to you that the value of n must be 2 in order to make the numerator equal to the denominator.
