Question 1204541
9% per year decrease means keeping 91% each year.
3% per year decrease means keeping 97% each year.


{{{5000*0.91^x=3000*0.97^x}}}

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{{{log((5000))+x*log((0.91))=log((3000))+x*log((0.97))}}}

{{{log((5000))-log((3000))=x*log((0.97))-x*log((0.91))}}}

{{{3*log((5))-3*log((3))=x(log((0.97))-log((0.91)))}}}

{{{x=3(log((5))-log((3)))/(log((0.97))-log((0.91)))}}}

{{{x=3(0.69897-0.47712)/(-0.013228+0.0409586)}}}

{{{cross(x=24)}}}


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Retry -------
{{{log((5000))+x*log((0.91))=log((3000))+x*log((0.97))}}}
{{{log((5/3))=x*log((0.97))-x*log((0.91))}}}
{{{log((5/3))=x(log((0.97/0.91)))}}}

{{{x=(log((5/3)))/(log((97/91)))}}}

{{{x=0.221849/0.02773}}}

{{{highlight(x=8.00)}}}