document.write( "Question 53100: There are 850 Douglas Fir and Ponderosa pine trees in a section of forest. The company paid an average of $300 for each Douglas fir and $225 for each Ponderosa pine. If the company paid $217,500 for the trees, how many of each kind did the company buy? \n" ); document.write( "

Algebra.Com's Answer #35404 by funmath(2933) $\"\"$ $\"About$

You can put this solution on YOUR website!
I answered this for a student yesterday who was told she had to use substitution or elimination to solve it. If you have to do that look back at yesterday's answers. I'm going to show you how to solve this using only one variable, thus avoiding a system of two equations.
\n" ); document.write( "Firs+pines=850
\n" ); document.write( "Let number of firs=x
\n" ); document.write( "Then number of pines:850-x
\n" ); document.write( "Cost of firs is 300*number of firs:300x
\n" ); document.write( "Cost of pines is 225*number of pines:250(850-x)
\n" ); document.write( "Total:217,500
\n" ); document.write( "Problem to solve:
\n" ); document.write( "300x+225(850-x)=217,500
\n" ); document.write( "300x+191,250-225x=217,500
\n" ); document.write( "(300-225)x+191,250=217,500
\n" ); document.write( "75x+191,250=217,500
\n" ); document.write( "75x+191,250-191,250=217,500-191,250
\n" ); document.write( "75x=26,250
\n" ); document.write( "75x/75=26,250/75
\n" ); document.write( "x=350
\n" ); document.write( "Number of firs:x=350
\n" ); document.write( "Number of pines:850-x=850-350=500
\n" ); document.write( "--------------------------------------
\n" ); document.write( "Check:
\n" ); document.write( "300(350)+225(500)=217,500
\n" ); document.write( "105,000+112,500=217,500
\n" ); document.write( "Seems resonable.
\n" ); document.write( " \n" ); document.write( "

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