document.write( "Question 880137: A car travels for 100 miles at a uniform speed. If the speed is increased by 5 miles per hour, the trip would take one hour less time. what is the car's original speed? \n" ); document.write( "

Algebra.Com's Answer #531231 by josmiceli(19441) $\"\"$ $\"About$

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(1) $\"+100+=+r%2At+\"$
\n" ); document.write( "(2) $\"+100+=+%28+r%2B5+%29%2A%28+t-1+%29+\"$
\n" ); document.write( "--------------------------
\n" ); document.write( "(1) $\"+t+=+100%2Fr+\"$
\n" ); document.write( "By substitution:
\n" ); document.write( "(2) $\"+100+=+%28+r+%2B+5+%29%2A%28+100%2Fr+-+1+%29+\"$
\n" ); document.write( "(2) $\"+100+=+100+%2B+500%2Fr+-+r+-+5+\"$
\n" ); document.write( "(2) $\"+r+%2B+5+=+500%2Fr+\"$
\n" ); document.write( "(2) $\"+r%5E2+%2B+5r+=+500+\"$
\n" ); document.write( "(2) $\"+r%5E2+%2B+5r+%2B+%28+5%2F2%29%5E2+=+500+%2B+%285%2F2%29%5E2+\"$
\n" ); document.write( "(2) $\"+r%5E2+%2B+5r+%2B+25%2F4+=+2000%2F4+%2B+25%2F4+\"$
\n" ); document.write( "(2) $\"+r%5E2+%2B+5r+%2B+25%2F4+=+2025%2F4+\"$
\n" ); document.write( "(2) $\"+%28+r+%2B+5%2F2+%29%5E2+=+%28+45%2F2+%29%5E2+\"$
\n" ); document.write( "(2) $\"+r+%2B+5%2F2+=+45%2F2+\"$
\n" ); document.write( "(2) $\"+r+=+40%2F2+\"$
\n" ); document.write( "(2) $\"+r+=+20+\"$
\n" ); document.write( "The car's original speed was 20 mi/hr
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+100+=+r%2At+\"$
\n" ); document.write( "(1) $\"+100+=+20t+\"$
\n" ); document.write( "(1) $\"+t+=+5+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+100+=+%28+r%2B5+%29%2A%28+t-1+%29+\"$
\n" ); document.write( "(2) $\"+100+=+%28+20%2B5+%29%2A%28+t-1+%29+\"$
\n" ); document.write( "(2) $\"+100+=+25t+-+25+\"$
\n" ); document.write( "(2) $\"+25t+=+125+\"$
\n" ); document.write( "(2) $\"+t+=+5+\"$
\n" ); document.write( "OK\r
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