document.write( "Question 367596: Dal and Kim can assemble a swing set in 1 1/2 hr. Working alone, it takes Kim 4 hr longer than Dal to assemble the swing set. How long would it take Dal, working alone, to assemble the swing set? I do not have a clue how to set this up Please help!!! \n" ); document.write( "
Algebra.Com's Answer #262018 by mananth(16946)\"\" \"About 
You can put this solution on YOUR website!
Dal and Kim can assemble a swing set in 1 1/2 hr. Working alone, it takes Kim 4 hr longer than Dal to assemble the swing set. How long would it take Dal, working alone, to assemble the swing set?
\n" ); document.write( "..
\n" ); document.write( "let Dal assemble in x hours
\n" ); document.write( "so he does 1/x of the job in 1 hour
\n" ); document.write( "..
\n" ); document.write( "kim takes (x+4) hours
\n" ); document.write( "so he does 1/(x+4) of the job in 1 hour.
\n" ); document.write( "..
\n" ); document.write( "Together they assemble in 3/2 hours
\n" ); document.write( "..
\n" ); document.write( "1/x + 1/(x+4) = 3/2
\n" ); document.write( "(x+4+x)/x(x+4)= 3/2
\n" ); document.write( "2x+4 /x(x+4)= 3/2
\n" ); document.write( "2(2x+4)=3x(x+4)
\n" ); document.write( "4x+8 = 3x^2+12x
\n" ); document.write( "3x^2-4x+12x-8 =0
\n" ); document.write( "3x^2+8x-8=0
\n" ); document.write( "..
\n" ); document.write( "find the roots by quadratic equation
\n" ); document.write( "discriminant = 160
\n" ); document.write( "x1= (-8+sqrt(160))/6
\n" ); document.write( "0.77 hours
\n" ); document.write( "Dal takes 0.77 hours to complete the job alone\r
\n" ); document.write( "\n" ); document.write( "...
\n" ); document.write( "m.ananth@hotmail.ca \n" ); document.write( "
\n" );