document.write( "Question 178957: The sume of the reciprocals of two consecutive odd integers is 20/99. Find the integers.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "A plane and a truck leave the same town at sunrise and head for a town 450 miles away. The spead of the plane is 3 times the speed of the truck, and the plane arrives 6 hours ahead of the truck. Find the speed of the plane.\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #133903 by Mathtut(3670)\"\" \"About 
You can put this solution on YOUR website!
let the integers be a and a+2
\n" ); document.write( ":
\n" ); document.write( "\"%281%2Fa%29%2B%281%2F%28a%2B2%29%29=20%2F99\"
\n" ); document.write( ":
\n" ); document.write( "\"%28a%2B2%2Ba%29%2Fa%28a%2B2%29=20%2F99\"
\n" ); document.write( ":
\n" ); document.write( "\"%282a%2B2%29%2F%28a%5E2%2B2a%29=20%2F99\"
\n" ); document.write( ":
\n" ); document.write( "\"198a%2B198=20a%5E2%2B40a\"
\n" ); document.write( ":
\n" ); document.write( "\"20a%5E2-158a-198=0\"
\n" ); document.write( ":
\n" ); document.write( "\"highlight%28a=9%29\"-1.1 is thrown out
\n" ); document.write( ":
\n" ); document.write( "integers are:\"system%289%2C11%29\"
\n" ); document.write( ":
\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"20x%5E2%2B-158x%2B-198+=+0\") has the following solutons:
\n" ); document.write( "
\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
\n" ); document.write( "
\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
\n" ); document.write( "
\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%28-158%29%5E2-4%2A20%2A-198=40804\".
\n" ); document.write( "
\n" ); document.write( " Discriminant d=40804 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--158%2B-sqrt%28+40804+%29%29%2F2%5Ca\".
\n" ); document.write( "
\n" ); document.write( " \"x%5B1%5D+=+%28-%28-158%29%2Bsqrt%28+40804+%29%29%2F2%5C20+=+9\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-158%29-sqrt%28+40804+%29%29%2F2%5C20+=+-1.1\"
\n" ); document.write( "
\n" ); document.write( " Quadratic expression \"20x%5E2%2B-158x%2B-198\" can be factored:
\n" ); document.write( " \"20x%5E2%2B-158x%2B-198+=+%28x-9%29%2A%28x--1.1%29\"
\n" ); document.write( " Again, the answer is: 9, -1.1.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+20%2Ax%5E2%2B-158%2Ax%2B-198+%29\"
\n" ); document.write( "
\n" ); document.write( "
\n" );