SOLUTION: A jet plane, flying 165 mph faster than a propeller plane, travels 2970 miles in 3 hours less time than the propeller plane takes to fly the same distance. How fast does each

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Question 704497:
A jet plane, flying 165 mph faster than a propeller plane, travels 2970 miles in 3 hours less time than the propeller plane takes to fly the same distance. How fast does each plane fly?

Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
D=RT
2970=(165+R)(T-3)
2970=RT
T=2970/R
2970=(165+R)(2970/R-3)
2970=165*2970/R-3R+2970R/R-3*165
2970=490050/R-3R+2970-495
2970-2970+495=490050/R-3R
495=(490050-3R^2)/R
495R=490050-3R^2
3R^2+495R-490050=0
3(R^2+165-163350)=0
3(R-330)(R+495)=0
R-330=0
R=330 RATE OF THE PROPELLER PLANE.
330+165=495 RATE OF THE JET.
2970=330T
2790/330=T
T=9 HOURS FOR THE PROPELLAR PLANE.
PROOF:
2970=495(9-3)
2970=495*6
2970=2970