SOLUTION: Log(12)=log(x)+log(7×x)

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Question 1146989: Log(12)=log(x)+log(7×x)
Found 3 solutions by josgarithmetic, Alan3354, ikleyn:
Answer by josgarithmetic(39623)   (Show Source): You can put this solution on YOUR website!

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
Log(12)=log(x)+log(7x)
Log(12)=log(x*7x) = log(7x^2)
7x^2 = 12
x^2 = 12/7
x = sqrt(12)/sqrt(7) = sqrt(7*12)/7
x = 2sqrt(21)/7
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The negative square root is not allowed.
Answer by ikleyn(52834)   (Show Source): You can put this solution on YOUR website!
.

Log(12) = log(x) + log(7×x)     (1)


I read 7×x as 7x.  Then  (1) is equivalent to


log(12) = log(x*7x)


log(12) = log(7x^2)


12 = 7x^2


x^2 = 


x =  = .    


ANSWER.   x= .


Solved.


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Be aware :   the "solution" by  @josgarithmtic is   TOTALLY  WRONG  (!) 

If you are a novice at this forum, you need to know that @josgarithmetic is a "punishement" of this forum.


    He doesn't know Math;                                                                               (1)

    he can not read the formulation of Math problems correctly;                                         (2)

    he can not solve Math problem correctly and produces every second or third solution incorrectly;    (3)

    he can not explain the solutions in a right way.                                                    (4)


    Every day he tries to prove something to himself and to other tutors, but every time he only proves 
    these statements (1), (2), (3) and (4) again and again.


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