What is the answer to 81*9^{-2b-2}=27 ?

The answer to 81*9^{-2b-2}=27 is b=-3/4

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81*9^{-2b-2}=27

81 \cdot 9^{- 2 b - 2} = 27

b = - \frac{3}{4}

Decimal Notation

b = - 0.75

Solution steps

81 \cdot 9^{- 2 b - 2} = 27

Divide both sides by

81

9^{- 2 b - 2} = \frac{1}{3}

Apply exponent rules

2 (- 2 b - 2) = - 1

Solve

2 (- 2 b - 2) = - 1 : b = - \frac{3}{4}

b = - \frac{3}{4}

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