Question 211676: I need help figuring out an equation for this problem I do not want the answer just an equation so I can figure it out myself please !!
A plane flies 440 miles with the wind and 350 miles against the wind in the same length of time. If the speed of the wind is 27 mph, what is the speed of the plane in still air?
Answer by checkley77(12844)   (Show Source):
You can put this solution on YOUR website! D=RT OR T=D/R
T=440/(R+27)
T=350/(R-27)
BECAUSE THE TIMES ARE THE SAME WE SET THESE TWO EQUATIONS EQUAL.
440/(R+27)=350/(R-27)
440(R-27)=350(R+27)
440R-11,880=350R+9,450
440R-350R=9,450=11,880
90R=21,330
R=21,330/90
R=237 MPH IS THE SPEED OF THE PLANE.
PROOF:
440/(237+27)=350/237-27)
440/264=350/210
1.6667=1.6667
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