What equation is equivalent to 9x - 3 = 729? 9^x - 3 = 9^81
9^x - 3 = 9^3
3^x - 3 = 3^6
3^2x - 3 = 3^6

9514 1404 393

  b.  9^(x-3) = 9^3

Step-by-step explanation:

Realizing that 729 = 9^3, we can rewrite the equation ...

  9^(x -3) = 729

as ...

  9^(x -3) = 9^3 . . . . . . matches the second selection

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Recognizing that 9 = 3^2, a couple of other equivalent forms can be made.

  (3^2)^(x -3) = (3^2)^3

  3^(2x-6) = 3^6

or, taking the square root, ...

  3^(x -3) = 3^3

None of these forms match any answer choices.

The solution will be found by matching exponents:

  x -3 = 3

  x = 6

step-by-step explanation: