Log(2x+1)+log(x)=log(21)

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1 Answer

log(x(2x+1))=log(21). So 2x^2+x-21=0=(2x+7)(x-3); x=-7/2 or 3. The negative solution has to be rejected because log(2x+1) and log(x) cannot be evaluated. So x=3.

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