document.write( "Question 738955: From her house, Ann drove to her grandmother's at an average speed of 60 miles per hour. She returned over the Same route at average speed of 45 miles per hour. If ann spent 7 hours traveling, how many miles is Ann's grandmother's house from her house?
\n" ); document.write( "I have no idea what to do? \n" ); document.write( "

Algebra.Com's Answer #450978 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+t+\"$ = her time in hrs for the 1st trip
\n" ); document.write( " $\"+7-t+\"$ = her time for the trip back
\n" ); document.write( "Let $\"+d+\"$ = distance to grandmother's house
\n" ); document.write( "----------------
\n" ); document.write( "(1) $\"+d+=+60t+\"$
\n" ); document.write( "(2) $\"+d+=+45%2A%28+7+-+t+%29+\"$
\n" ); document.write( "--------------------
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+60t+=+45%2A%28+7+-+t+%29+\"$
\n" ); document.write( "(2) $\"+60t+=+315+-+45t+\"$
\n" ); document.write( "(2) $\"+105t+=+315+\"$
\n" ); document.write( "(2) $\"+t+=+3++\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+d+=+60t+\"$
\n" ); document.write( "(1) $\"+d+=+60%2A3+\"$
\n" ); document.write( "(1) $\"+d+=+180+\"$
\n" ); document.write( "The distance to grandmother's house is 180 mi
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+d+=+45%2A%28+7+-+t+%29+\"$
\n" ); document.write( "(2) $\"+180+=+45%2A%28+7+-+3+%29+\"$
\n" ); document.write( "(2) $\"+180+=+45%2A4+\"$
\n" ); document.write( "(2) $\"+180+=+180+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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