document.write( "Question 601553: A newer model jet plan can travel 200 mph faster than a an older model. The newer model can travel 1200 miles in the same time that the older model can travel 900 miles. What is the rate of the older model jet plane? \n" ); document.write( "

Algebra.Com's Answer #379849 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+s+\"$ = the speed of the older model
\n" ); document.write( "Let $\"+t+\"$ = time in hours older model takes to travel 900 mi
\n" ); document.write( "and newer model takes to travel 1200 mi
\n" ); document.write( "-----------------
\n" ); document.write( "Equation for older model:
\n" ); document.write( "(1) $\"+900+=+s%2At+\"$
\n" ); document.write( "Equation for newer model:
\n" ); document.write( "(2) $\"+1200+=+%28+s+%2B+200+%29%2At+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+1200+=+s%2At+%2B+200t+\"$
\n" ); document.write( "(2) $\"+1200+=+900+%2B+200t+\"$
\n" ); document.write( "(2) $\"+200t+=+300+\"$
\n" ); document.write( "(2) $\"+t+=+1.5+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+900+=+s%2A1.5+\"$
\n" ); document.write( "(1) $\"+s+=+900%2F1.5+\"$
\n" ); document.write( "(1) $\"+s+=+600+\"$
\n" ); document.write( "The speed of the older model is 600 mi/hr
\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+1200+=+%28+s+%2B+200+%29%2At+\"$
\n" ); document.write( "(2) $\"+1200+=+%28+600+%2B+200+%29%2At+\"$
\n" ); document.write( "(2) $\"+t+=+1200%2F800+\"$
\n" ); document.write( "(2) $\"+t+=+1.5+\"$
\n" ); document.write( "OK \n" ); document.write( "

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