document.write( "Question 975639: Julia is starting her own on-line business selling jewellery that she makes. It cost her $3000 to buy a new computer, and her monthly expenses for Internet service and materials average about $170 per month. If her revenue for each month averages about $420, how long will it be before she starts to earn a profit? \n" ); document.write( "

Algebra.Com's Answer #599154 by Fombitz(32388) $\"\"$ $\"About$

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The equation for costs is
\n" ); document.write( " $\"C%28t%29=3000%2B170t\"$
\n" ); document.write( "where t is measured in months.
\n" ); document.write( "The equation for revenues is,
\n" ); document.write( " $\"R%28t%29=420t\"$
\n" ); document.write( "Profit equals revenue minus costs,
\n" ); document.write( "Find when P reaches zero.
\n" ); document.write( " $\"P=R-C\"$
\n" ); document.write( " $\"P=420t-3000-170t\"$
\n" ); document.write( " $\"P=250t-3000\"$
\n" ); document.write( " $\"250t=3000\"$
\n" ); document.write( " $\"t=3000%2F250\"$
\n" ); document.write( " $\"t=12\"$ $\"months\"$
\n" ); document.write( "So in the 13th month from starting she'll have a profit.
\n" ); document.write( " \n" ); document.write( "

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