SOLUTION: I need help solving these problems. {{{ 2log(3,x)-log(3,x-4)=(2)+log(3,2)}}} and {{{(1/2)log (4x+5)= log x}}}

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Question 458375: I need help solving these problems.

and

Found 2 solutions by josmiceli, lwsshak3:
Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
Use the rule
and the rule
and the rule
----------------------------------------







Use quadratic formula









and


check:

OK
---------



Square both sides


Complete the square:







also



Answer by lwsshak3(11628)   (Show Source): You can put this solution on YOUR website!
2log3(x)-log3(x-4)=2+log3(2)
(1/2)log (4x+5)= log x
..
2log3(x)-log3(x-4)=2+log3(2)
2log3(x)-log3(x-4)-log3(2)=2
2log3(x)-(log3(x-4)+log3(2))=2
place under single log
log3[x^2/(x-4)(2)]=2
convert to exponential form (base(3) raised to log of number(2)=number[x^2/(x-4)(2)]
3^2=x^2/(x-4)(2)=9
x^2/(2x-8)=9
x^2=18x-72
x^2-18x+72=0
(x-9)(x-8)=0
x=9
or
x=8
...
(1/2)log (4x+5)= log x
(1/2)log (4x+5)- log x=0
log[(4x+5)^1/2/x]=0
10^0=(4x+5)^1/2/x=1
(4x+5)^1/2=x
square both sides
4x+5=x^2
x^2-4x-5=0
(x-5)(x+1)=0
x=5
or
x=-1 (reject, ( x>0)

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