document.write( "Question 1043740: Please help me fill in the blanks:
\n" ); document.write( "Andrew and Bobby both opened restaurants at the same time. Andrew reported that on the first week after opening his restaurant, he had a profit of $500, and every week after that, his profit continually increased by 12%. Bobby reported that on the first week after opening his restaurant, he had a profit of $600, and every week after that, his profit continually increased by 8%.\r
\n" ); document.write( "\n" ); document.write( "Use the information given above to determine how long Bobby will have a higher profit than Andrew.\r
\n" ); document.write( "\n" ); document.write( "The first week Andrew will have a higher profit than Bobby will occur ___ weeks after he opens his restaurant.\r
\n" ); document.write( "\n" ); document.write( "The first week when Andrew's profit is higher than Bobby's, Bobby starts an advertising campaign that makes his weekly profit begin to increase by 15%. Taking this change into account, what will Bobby's weekly profit be 14 weeks after opening his restaurant? ___
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Algebra.Com's Answer #658918 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
Let \"+P+\" = profit after \"+n+\" weeks
\n" ); document.write( "Let \"+A+\" = the amount of the 1st weeks profit
\n" ); document.write( "Let \"+r+\" = weekly increase in profit
\n" ); document.write( "-------------------------------
\n" ); document.write( "The equation for both of them is:
\n" ); document.write( "\"+P+=+A%2A%28+1+%2B+r+%29%5En+\"
\n" ); document.write( "-----------------------------
\n" ); document.write( "Andrew's equation:
\n" ); document.write( "\"+P+=+500%2A%28+1+%2B+.12+%29%5En+\"
\n" ); document.write( "Bobby's equation:
\n" ); document.write( "\"+P+=+600%2A%28+1+%2B+.08+%29%5En+\"
\n" ); document.write( "------------------------
\n" ); document.write( "Note that the 1st week for each will be \"+n+=+0+\"
\n" ); document.write( "Find the week when their profits are equal
\n" ); document.write( "\"+500%2A%28+1+%2B+.12+%29%5En+=+600%2A%28+1+%2B+.08+%29%5En+\"
\n" ); document.write( "\"+500%2A1.12%5En+=+600%2A1.08%5En+\"
\n" ); document.write( "\"+1.12%5En+%2F+1.08%5En+=+600%2F500+\"
\n" ); document.write( "\"+%28+1.12%2F1.08+%29%5En+=+1.2+\"
\n" ); document.write( "Take the log of both sides
\n" ); document.write( "
\n" ); document.write( "\"+n%2A%28+.049218+-+.033424+%29+=+.079181+\"
\n" ); document.write( "\"+.015794n+=+.079181+\"
\n" ); document.write( "\"+n+=+5.01336+\"
\n" ); document.write( "-----------------
\n" ); document.write( "If I start with week \"0\", this is after \"+5+%2B+1+=+6+\" weeks, they
\n" ); document.write( "make the same profit, so
\n" ); document.write( "The first week Andrew will have a higher profit than Bobby will occur 7 weeks after he opens his restaurant.
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\n" ); document.write( "After 7 weeks, Bobby's profit is:
\n" ); document.write( "\"+P+=+600%2A%28+1+%2B+.08+%29%5E6+\" ( 1st week is week \"0\" )
\n" ); document.write( "\"+P+=+600%2A1.08%5E6+\"
\n" ); document.write( "\"+P+=+600%2A+1.58687+\"
\n" ); document.write( "\"+P+=+952.12+\"
\n" ); document.write( "Then Bobby's equation becomes:
\n" ); document.write( "\"+P+=+952.12%2A%28+1+%2B+.15+%29%5En+\"
\n" ); document.write( "\"+n+\" is now from \"+n+=+6+\" to \"+n+=+13+\"
\n" ); document.write( "This is 7 weeks, but the 1st week is week \"+0+\", so
\n" ); document.write( "\"+P+=+952.12%2A%28+1+%2B+.15+%29%5E6+\"
\n" ); document.write( "\"+P+=+952.12%2A1.15%5E6+\"
\n" ); document.write( "\"+P+=+952.12%2A2.31306+\"
\n" ); document.write( "\"+P+=+2202.31\"
\n" ); document.write( "What is Bobby's weekly profit 14 weeks after opening his restaurant?
\n" ); document.write( "$2,202.31
\n" ); document.write( "-----------------
\n" ); document.write( "I could easily get this wrong.
\n" ); document.write( "Get another opinion, too.
\n" ); document.write( "
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