SOLUTION: HARD!! algebra (Linear Systems) question? An Airplane cruises at 120km/h in still air. One day, when the wind was blowing steady rom the west, the airplane travelled west (flying

Algebra ->  College  -> Linear Algebra -> SOLUTION: HARD!! algebra (Linear Systems) question? An Airplane cruises at 120km/h in still air. One day, when the wind was blowing steady rom the west, the airplane travelled west (flying       Log On


   



Question 355612: HARD!! algebra (Linear Systems) question?
An Airplane cruises at 120km/h in still air. One day, when the wind was blowing steady rom the west, the airplane travelled west (flying into the wind) and landed at its desination after 1.5h. The airplane's return trip (flying with the wind) was only 1.0 h long. On both legs, the airplane travelled at its cruising speed. (meausred with respect to the air surrounding the airplane).
Part A
Write a System of equations that would allow you to determine the speed of the wind blowing that day and the distance traveled each way
Part B
When solving the system of equations graphically, what equations would you enter into the equation editor (to make graphs on your calculator)
Part C
Indicate what the X and the Y represent

Well.... im stumpped...
y=1.5(120 - x)= 180 -1.5x ?? then what
y=1.0(120 + x)=120 + 1.0x ??
I'm so confused please can someone help me:(

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
speed of plane in still air = 120mph
let speed of wind be x mph
against wind the speed will be 120-x mph
with wind the speed will be 120+x mph
..
distance trraveled forward = (120-x)*1.5
distance traveled return = (120+x)*1
x+120 = 180-1.5x
2.5x=60
x=60/2.5
x= 24 mph the speed of wind
...
the x axis represents the wind speed
the y axis represents the cruising speed.
Green line represents against wind
red line represents with wind.
they intesect at x = 24 the wind speed
graph%28500%2C500%2C-10%2C130%2C-10%2C200%2C%28x%2B120%29%2C%28-1.5x%2B180%29%29