document.write( "Question 615427: If Kevin walks to school and rides his bicycle back home it takes him 90 minutes. If he rider his bicycle both ways it takes him 30 minutes. How would it take him to make the trip to school and back walking both ways? \n" ); document.write( "

Algebra.Com's Answer #387180 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+d+\"$ = the one-way distance from home to school
\n" ); document.write( "Let $\"+w+\"$ = his speed walking
\n" ); document.write( "Let $\"r+\"$ = his speed riding
\n" ); document.write( "Let $\"+t+\"$ = his time walking one-way
\n" ); document.write( "------------------------
\n" ); document.write( "Walking and riding:
\n" ); document.write( " $\"+d+=+w%2At+\"$
\n" ); document.write( " $\"+d+=+r%2A%28+1.5+-+t+%29+\"$
\n" ); document.write( "---------------
\n" ); document.write( "Just riding:
\n" ); document.write( " $\"+2d+=+r%2A.5+\"$
\n" ); document.write( "-----------
\n" ); document.write( "It doesn't really matter what I say the distance is.
\n" ); document.write( "No units of speed or distance are given. I will say
\n" ); document.write( "the distance is $\"+1+\"$ unit of length and the speeds
\n" ); document.write( "are units/hour.
\n" ); document.write( "--------------
\n" ); document.write( "(1) $\"+1+=+w%2At+\"$
\n" ); document.write( "(2) $\"+1+=+r%2A%28+1.5+-+t+%29+\"$
\n" ); document.write( "(3) $\"+2+=+.5r+\"$
\n" ); document.write( "-------------
\n" ); document.write( "(2) $\"+1+=+1.5r+-+r%2At+\"$
\n" ); document.write( "and
\n" ); document.write( "(3) $\"+r+=+2%2F.5+\"$
\n" ); document.write( "(3) $\"+r+=+4+\"$ units/hr
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+1+=+1.5%2A4+-+4t+\"$
\n" ); document.write( "(2) $\"+4t+=+6+-+1+\"$
\n" ); document.write( "(2) $\"+4t+=+5+\"$
\n" ); document.write( "(2) $\"+t+=+1.25+\"$ hrs
\n" ); document.write( "-------------
\n" ); document.write( "(1) $\"+1+=+w%2A1.25+\"$
\n" ); document.write( "(1) $\"+w+=+.8+\"$ units/hr
\n" ); document.write( "--------------
\n" ); document.write( " $\"+2%2A1+=+w%2A%282t%29+\"$
\n" ); document.write( " $\"+2t+=+2%2Fw+\"$
\n" ); document.write( " $\"+2t+=++2%2F.8+\"$
\n" ); document.write( " $\"+2t+=+2.5+\"$
\n" ); document.write( "It will take him 2.5 hrs walking both ways
\n" ); document.write( "-------
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+1+=+1.5r+-+r%2At+\"$
\n" ); document.write( "(2) $\"+1+=+1.5%2A4+-+4%2A1.25+\"$
\n" ); document.write( "(2) $\"+1+=+6+-+5+\"$
\n" ); document.write( " $\"+1+=+1+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

\n" );