SOLUTION: Really need help on logarithm problems! log(x)+log(x-15)=2 ln(x+12)-ln(x)= ln(x+5) e^2x+2e^x-3=0

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Question 998450: Really need help on logarithm problems!
log(x)+log(x-15)=2
ln(x+12)-ln(x)= ln(x+5)
e^2x+2e^x-3=0
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
log(x)+log(x-15)=2

Assumed base ten:
log%28%28x%29%29%2Blog%28%28x-15%29%29=2

Rule of Logarithms says do this.
log%28%28x%28x-15%29%29%29=2

Put into exponential form:
10%5E2=x%28x-15%29


Simpler algebra from there.
x%5E2-15x-100=0
%28x-10%29%28x%2B5%29=0
-
Either x=10 or x=-5.

Review laws of exponents and rules of logarithms.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Really need help on logarithm problems!
log(x)+log(x-15)=2
ln(x+12)-ln(x)= ln(x+5)
e^2x+2e^x-3=0
Too many problems

1. highlight_green%28x+=+20%29       OR    x = - 5 (ignore)

2. Apply the same method/concept in 1.

3. e%5E%282x%29+%2B+2e%5Ex+-+3+=+0

  -  Factor this to get: %28e%5Ex+-+1%29%28e%5Ex+%2B+3%29+=+0

  -  Set each factor equal to 0

  -  Solve for x and IGNORE any EXTRANEOUS solution