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Solve.

Log2 (8x) - Log2 (x^2-1) = Log2 3

1 Answer

3 votes

Answer:

x = 3

Explanation:

Taking the antilog, the equation becomes ...

... 8x/(x^2 -1) = 3

Multiplying by the denominator, you have ...

... 8x = 3(x^2 -1)

Subtracting the left side to put into standard form gives ...

... 3x^2 -8x -3 = 0

This can be factored as ...

... (3x +1)(x -3) = 0

so the values of x that make these factors zero are ...

... x = -1/3 . . . and . . . x = 3

The original equation requires x > 1, so the only viable solution here is ...

... x = 3

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We can also solve this graphically to get the same result.

Solve. Log2 (8x) - Log2 (x^2-1) = Log2 3-example-1
User Bihire Boris
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