SOLUTION: Solve problem exactly ln (x + 1) = ln (3x + 1)- ln x

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Question 4558: Solve problem exactly
ln (x + 1) = ln (3x + 1)- ln x

Answer by rapaljer(4671)   (Show Source): You can put this solution on YOUR website!


By the second law of logarithms,


Now, since there are ln s on both sides of the equation, raise both sides as a power of e:




Multiply both sides of this equation by x



Set equal to zero:


Solve by quadratic formula, where and a= 1, b= -2, c = -1.






Factor the numerator, so you can reduce the fraction:

or

However, the second solution is a negative number, which is NOT allowed in the last ln expression. So the only solution is

R^2 at SCC

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