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  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

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Topic review (newest first)

irspow
2005-11-30 10:02:50

I came up with the same answer, but was a little puzzled at mathsyperson's approach.  I am always amazed at the different approaches individuals will take.  I did it like this.

     3ln(-3x+5) = -9     divide by 3

     ln(-3x+5) = -3       raise to e

     -3x+5 = e^-3        subtract 5

     -3x = e^-3 - 5       divide by -3

      x = (e^-3 - 5) / -3

mathsyperson
2005-11-29 11:48:28

3ln(-3x+5) = -9

Using alnb = lnb^a : ln(-3x+5)³ = -9

Raise to the power of e: (-3x+5)³ = e^-9

Cube root: -3x+5 = e^-3

Solve: -3x = e^-3 - 5
x = -(e^-3 - 5)/3

username
2005-11-29 11:38:04

solve for x

3ln(-3x+5) = -9

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