document.write( "Question 333295: One plane took off from the San Fransisco , traveling east. At the same time another plane took off from the same airport, traveling west. The plane traveling east was going 120 miles per hour faster than the plane traveling west. After three hours, the planes were 2,400 miles apart. How fast was each plane going? \n" ); document.write( "
Algebra.Com's Answer #238833 by mananth(16946)\"\" \"About 
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traveling east. speed= 120 miles per hour faster than the plane traveling west. \r
\n" ); document.write( "\n" ); document.write( "After three hours, the planes were 2,400 miles apart. How fast was each
\n" ); document.write( "let speed of west bound plane be x mph
\n" ); document.write( "east bound plane speed will be x-120 mph
\n" ); document.write( "..
\n" ); document.write( "distance = speed * time
\n" ); document.write( "time = 3hours
\n" ); document.write( "distance traveled by one plane = 3x
\n" ); document.write( "distance by other plane = (x-120)*3
\n" ); document.write( "..
\n" ); document.write( "3x+3(x-120)=2400
\n" ); document.write( "3x+3x-360=2400
\n" ); document.write( "6x=2760
\n" ); document.write( "x=460 speed of west bound plane.
\n" ); document.write( "East bound plane speed =460-120= 340 mph
\n" ); document.write( "CHECK effective speed = 340+460 = 800 mph
\n" ); document.write( "distance = 2400 miles
\n" ); document.write( "time = distance / speed = 2400/800 = 3 hours
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