document.write( "Question 904050: Imogene's car traveled 336 miles averaging a certain speed. If the car had gone 6 mph faster, the trip would have takes 1 hour less. Find the average speed. \n" ); document.write( "
Algebra.Com's Answer #548503 by ewatrrr(24785)\"\" \"About 
You can put this solution on YOUR website!
\"336mi%2Fr+-+336%2F%28r%2B6%29+=+1\" |Multiplying thru by r(r+6) so as all denominators = 1
\n" ); document.write( "336(r+7) - 336r = r(r+6)
\n" ); document.write( "r^2 + 6r - 2352 = 0 (Tossing out the negative solution for unit measure)
\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B6x%2B-2352+=+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=%286%29%5E2-4%2A1%2A-2352=9444\".
\n" ); document.write( "
\n" ); document.write( " Discriminant d=9444 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-6%2B-sqrt%28+9444+%29%29%2F2%5Ca\".
\n" ); document.write( "
\n" ); document.write( " \"x%5B1%5D+=+%28-%286%29%2Bsqrt%28+9444+%29%29%2F2%5C1+=+45.5901224530254\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%286%29-sqrt%28+9444+%29%29%2F2%5C1+=+-51.5901224530254\"
\n" ); document.write( "
\n" ); document.write( " Quadratic expression \"1x%5E2%2B6x%2B-2352\" can be factored:
\n" ); document.write( " \"1x%5E2%2B6x%2B-2352+=+1%28x-45.5901224530254%29%2A%28x--51.5901224530254%29\"
\n" ); document.write( " Again, the answer is: 45.5901224530254, -51.5901224530254.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B6%2Ax%2B-2352+%29\"
\n" ); document.write( "
\n" ); document.write( "
\n" );