document.write( "Question 934299: In 1980 the average price of a home in Brainerd County was $90,000. By 1987 the average price of a home was $125,000. Write a linear model for the price of a home, P, in Brainerd County as a function of the year, t. Let t = 0 correspond to 1980. \n" ); document.write( "

Algebra.Com's Answer #567347 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Plot ( t,P )
\n" ); document.write( "Use the general point-slope formula
\n" ); document.write( "with $\"+P+\"$ in thousands of dollars
\n" ); document.write( " $\"+%28+P+-+90+%29+%2F+%28+t+-+0+%29+=+%28+125+-+90+%29+%2F+%28+7+-+0+%29+\"$
\n" ); document.write( " $\"+%28+P+-+90+%29+%2F+t+=+35+%2F+7+\"$
\n" ); document.write( "Multiply both sides by $\"+7t+\"$
\n" ); document.write( " $\"+7%2A%28+P+-+90+%29+=+35t+\"$
\n" ); document.write( " $\"+7P+-+630+=+35t+\"$
\n" ); document.write( " $\"+7P+=+35t+%2B+630+\"$
\n" ); document.write( " $\"+P+=+5t+%2B+90+\"$
\n" ); document.write( "-----------------
\n" ); document.write( "check:
\n" ); document.write( "does it go through ( 0,90 ) ?
\n" ); document.write( " $\"+90+=+5%2A0+%2B+90+\"$
\n" ); document.write( " $\"+90+=+90+\"$
\n" ); document.write( "OK
\n" ); document.write( "dos it go through ( 7,125 ) ?
\n" ); document.write( " $\"+125+=+5%2A7+%2B+90+\"$
\n" ); document.write( " $\"+125+=+125+\"$
\n" ); document.write( "OK
\n" ); document.write( "----------------
\n" ); document.write( "Heres the plot:
\n" ); document.write( " $\"+graph%28+400%2C+400%2C+-1%2C+8%2C+-10%2C+135%2C+5x+%2B+90+%29+\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );