SOLUTION: Two planes make an 800 mile flight, one flying 100 miles per hour faster than the other. The quicker plane makes the trip 4 hours faster. How long did it take the slower plane to

Question 442497: Two planes make an 800 mile flight, one flying 100 miles per hour faster than the other. The quicker plane makes the trip 4 hours faster. How long did it take the slower plane to complete the flight?

Answer by jorel1380(3719) (Show Source): You can put this solution on YOUR website!
800/x=800/(x+100)+4
800(x+100)=800x+4x2+400x
800x+80000=4x2+1200x
0=4x2+400x-80000
0=x2+100x-20000
0=(x+200)(x-100)
x=100 or -200. Throwing out the negative answer, we get the slow plane flying at 100mph, the fast plane moving at 200mph..
RELATED QUESTIONS
Two planes make a 1000 mile flight, one flying 75 miles per hour faster than the other.... (answered by kevwill)

10. Two planes make a 1000 mile flight, one flying 75 miles per hour faster than the... (answered by lynnlo)

Two planes make a 1680 mile flight, one flying 10 miles per hour faster than the other.... (answered by josgarithmetic,MathTherapy)

Two planes make a 1000 mile flight, one flying 75 miles per hour faster than the other.... (answered by josgarithmetic,MathTherapy)

Two planes make a 1000 mile flight, one flying 75 mph faster than the other. the quicker (answered by kevwill)

two planes leave simultaneously from the same airport, one flying due east and the other... (answered by Cintchr)

Two planes make a 600 miles flight one flying 50 mph faster than the other if the slower... (answered by ikleyn)

Two planes leave simultaneously from the same airport, one flying due east and the other... (answered by checkley77,ankor@dixie-net.com)

Two planes leave simultaneously from Chicago's O'Hare Airport, one flying due north and... (answered by josgarithmetic)