A few days ago
Anonymous

Indices question?

What are the steps to solve this

3^(2x) – 7(3^(x)) = 18

Please list down clearly all steps taken to derive the answer. Thanks

Top 1 Answers
A few days ago
jsardi56

Favorite Answer

Let y = 3^x, then your equation becomes:

y^2 – 7y = 18

y^2 -7y -18 = 0

(y – 9)(y + 2) = 0

y = 9 ; y = -2[extraneous]

3^x = 9

3^x = 3^2

x = 2

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