document.write( "Question 1007320: While riding a bicycle one afternoon, Pete discovered that he could travel 15 miles while riding with a 6 mile per hour tailwind in the same amount of time that it took to travel 9 miles into the same wind. At what rate could Pete ride with no wind at all? \n" ); document.write( "
Algebra.Com's Answer #623270 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
Let \"+s+\" = his speed with no wind
\n" ); document.write( "\"+s+%2B+6+\" = his speed riding with the wind
\n" ); document.write( "\"+s+-+6+\" = his speed riding into the wind
\n" ); document.write( "Let \"+t+\" = his time in hrs riding both ways
\n" ); document.write( "-------------------------------------
\n" ); document.write( "Riding with the wind:
\n" ); document.write( "(1) \"+15+=+%28+s+%2B+6+%29%2At+\"
\n" ); document.write( "Riding against the wind:
\n" ); document.write( "(2) \"+9+=+%28+s+-+6+%29%2At+\"
\n" ); document.write( "--------------------
\n" ); document.write( "(1) \"+t+=+15%2F%28+s+%2B+6+%29+\"
\n" ); document.write( "Substitute this result into (2)
\n" ); document.write( "(2) \"+9+=+%28+s+-+6+%29%2A%28+15%2F%28+s+%2B+6+%29%29+\"
\n" ); document.write( "Multiply both sides by \"+s+%2B+6+\"
\n" ); document.write( "(2) \"+9%2A%28+s+%2B+6+%29+=+15%2A%28+s+-+6+%29+\"
\n" ); document.write( "(2) \"+9s+%2B+54+=+15s+-+90+\"
\n" ); document.write( "(2) \"+6s+=+144+\"
\n" ); document.write( "(2) \"+s+=+24+\"
\n" ); document.write( "His speed with no wind is 24 mi/hr
\n" ); document.write( "----------------
\n" ); document.write( "check:
\n" ); document.write( "(1) \"+15+=+%28+s+%2B+6+%29%2At+\"
\n" ); document.write( "(1) \"+15+=+%28+24+%2B+6+%29%2At+\"
\n" ); document.write( "(1) \"+15+=+30t+\"
\n" ); document.write( "(1) \"+t+=+1%2F2+\"
\n" ); document.write( "and
\n" ); document.write( "(2) \"+9+=+%28+s+-+6+%29%2At+\"
\n" ); document.write( "(2) \"+9+=+%28+24+-+6+%29%2At+\"
\n" ); document.write( "(2) \"+9+=+18t+\"
\n" ); document.write( "(2) \"+t+=+1%2F2+\"
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "
\n" );