document.write( "Question 730880: Jake can cut and split a cord of firewood in 6 fewer hours than Steve. When they work together, it takes them 4 hours. How long would it take each of them to do the job alone?
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #446892 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = number of hours it takes Jake to do the job if he worked alone\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = number of hours it takes Steve to do the job if he worked alone\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We are told that \"Jake can cut and split a cord of firewood in 6 fewer hours than Steve\", so\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = y - 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "-------------------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"When they work together, it takes them 4 hours\", we can construct this equation\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "1/x + 1/y = 1/4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4xy(1/x) + 4xy(1/y) = 4xy(1/4) ... multiply EVERY term by the LCD 4xy to clear out the fractions\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4y + 4x = xy\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4y + 4(y-6) = (y-6)y ... plug in x = y-6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4y + 4(y-6) = (y-6)y\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4y + 4y - 24 = y^2-6y\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "8y - 24 = y^2-6y\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "0 = y^2-6y-8y+24\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "0 = y^2-14y+24\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y^2-14y+24 = 0\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(y-12)(y-2) = 0\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y-12 = 0 or y-2 = 0\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = 12 or y = 2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the possible solutions for y are\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "y = 12 or y = 2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "If y = 2, then \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = y - 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = 2 - 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = -4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So y CANNOT be 2 because this makes x a negative number.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So toss out y = 2 as a solution\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "If y = 12, then\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = y - 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = 12 - 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x = 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So if y = 12, then x = 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Therefore, \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Jake can do the job in 6 hours if he worked alone. \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Steve can do the job in 12 hours if he worked alone.
\n" ); document.write( "
\n" );