SOLUTION: plane A is 40 miles south and 100 miles east of plane B. plane A is flying 2 miles west for ever mile it flies north, while plane B is flying 3 miles east for every mile it flies

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Question 510833: plane A is 40 miles south and 100 miles east of plane B. plane A is flying 2 miles west for ever mile it flies north, while plane B is flying 3 miles east for every mile it flies south. where do there paths cross?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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plane A is 40 miles south and 100 miles east of plane B. plane A is flying 2 miles west for ever mile it flies north, while plane B is flying 3 miles east for every mile it flies south. where do there paths cross?
:
Write a linear equation for the line taken by each plane
With O origin,
Plane B: When x = 0, y = 40
"plane B is flying 3 miles east for every mile it flies south."
Using the rise/run rule the slope will be -1/3 (negative because it's moving southward)
y = -1%2F3x + 40
+graph%28+300%2C+200%2C+-20%2C+130%2C+-10%2C+60%2C+-.333x%2B40%29+
:
Plane A: x intercept = +100, find the y intercept
"plane A is flying 2 miles west for ever mile it flies north,"
Slope = -1/2; find the y intercept (b)
-1%2F2(100) + b = 0
-50 + b = 0
b = 50
the equation for A: y = -1%2F2x + 50, plot this with B
intercept x=60 mi east, y=20 mi north
+graph%28+300%2C+200%2C+-20%2C+130%2C+-10%2C+60%2C+-.333x%2B40%2C+-.5x%2B50%29+