SOLUTION: help me solve ln(x^2 + 12)=ln x + ln 8

Question 67199This question is from textbook
: help me solve ln(x^2 + 12)=ln x + ln 8 This question is from textbook

Found 2 solutions by bam878s, funmath:
Answer by bam878s(77) (Show Source): You can put this solution on YOUR website!
This problem is simple once you utilize a common law of logarithms.
ln ab = ln a + ln b
On the right hand side of this equation we have ln x + ln 8. By using the above law, we can write this as ln 8x.
So, we have:
ln( + 12) = ln 8x. So now we know that + 12 = 8x
+ 12 = 8x
+ 12 - 8x = 0
- 8x + 12 = 0. We can solve this by using the quadratic formula, but an easier way would be to factor this out as follows:
- 8x + 12 = (x-6) * (x-2). So, we have:
(x-6)(x-2) = 0. We know that 0 * anything = 0, so now we can easily see that
x = 6 or x = 2.
Hope this helps!!
Answer by funmath(2933) (Show Source): You can put this solution on YOUR website!
Rules:
1.
2. If then
:
solve ln(x^2 + 12)=ln x + ln 8
rule 1
rule 2
set = to 0

Factor
x-2=0 or x-6=0
x-2+2=0+2 or x-6+6=0+6
x=2 or x=6
Check for extraneous solutions.

2.772588722=.6931471806+2.079441542
2.772588722=2.772588722 x=2 is valid

ln(48)=3.871201011
3.87201011=3.8712011 x=6 is valid, too.
or
Happy Calculating!!!
RELATED QUESTIONS
Solve ln(3x+8)=ln(2x+2)+ln(x-2) for x Please help... (answered by khwang)
Can some please help me solve for x? ln (4x � 8) � ln (x-1) = ln... (answered by josmiceli)
Solve: log base 4 (X) + Log base 8 (x) = 1 ln X/ln 4 + ln X/ln 8=1 2 ln X/2 ln 4 + ln... (answered by Fombitz)
ln (ln x) =... (answered by Fombitz)
Solve for x: ln(x^2-12)=... (answered by user_dude2008)
Solve for X... (answered by josgarithmetic,greenestamps)
ln(x+2)+lnx=ln(x+12) (answered by fractalier)
-could you please help me in this problem solve for x: ln(x-1)=ln(x-2)-ln... (answered by josgarithmetic)
ln(x)-ln(x-2)=ln(7) (answered by Nate)