document.write( "Question 314312: A marine platoon went on a 20 mile hike that took 6 hours to complete. for the first 12 miles the platoon hiked at a constant speed. For the last 8 miles he increased his speed by 1 mph. find the speed for the last part of the hike. \n" ); document.write( "

Algebra.Com's Answer #224870 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
Rate*Time=Distance
\n" ); document.write( " $\"+R1%2AT1=D1+\"$
\n" ); document.write( " $\"R1%2AT1=12\"$
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( " $\"R2%2AT2=8\"$
\n" ); document.write( " $\"R2=R1%2B1\"$
\n" ); document.write( " $\"%28R1%2B1%29%2AT2=8\"$
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( "You also know that
\n" ); document.write( " $\"T1%2BT2=6\"$
\n" ); document.write( ".
\n" ); document.write( ".
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\n" ); document.write( "From above,
\n" ); document.write( " $\"T1=+12%2FR1\"$
\n" ); document.write( " $\"T2+=+8%2F%28R1%2B1%29\"$
\n" ); document.write( "Substitute,
\n" ); document.write( " $\"T1%2BT2=6\"$
\n" ); document.write( " $\"+12%2FR1%2B8%2F%28R1%2B1%29=6\"$
\n" ); document.write( " $\"12%28R1%2B1%29%2B8R1=6R1%28R1%2B1%29\"$
\n" ); document.write( " $\"12R1%2B12%2B8R1=6R1%5E2%2B6R1\"$
\n" ); document.write( " $\"6R1%5E2-14R1-12=0\"$
\n" ); document.write( " $\"%286R1%2B4%29%28R1-3%29=0\"$
\n" ); document.write( "Two solutions but only positive solution makes sense in this problem.
\n" ); document.write( " $\"R1-3=0\"$
\n" ); document.write( " $\"R1=3\"$
\n" ); document.write( "Then from above,
\n" ); document.write( " $\"highlight_green%28R2=4%29\"$
\n" ); document.write( " \n" ); document.write( "

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