Let's begin by listing out the information given to us:
8 am
airplane #1: x = 80870 ft, v = -450 ft/ min
airplane #2: x = 5000 ft, v = 900ft/min
1. 
We must note that the airplanes are moving at a constant speed. The equation for the airplanes is given by:

2.
We equate equations 1 & 2 to get the time both airlanes will be at the same elevation. We have:

3.
The elevation at that time (when the elevations of the two airplanes are the same) is given by substituting the value of time into equations 1 & 2. We have:
 
 
        
             
        
        
        
Answer: 45°
Step-by-step explanation: add the angles together to get a total of 180°
 
        
             
        
        
        
Answer:
8.43
Step-by-step explanation:
8 + 10 + 10 + 10 + 6 + 7 + 8 = 59
59/7 = 8.43 (or keep as improper fraction)
 
        
             
        
        
        
Answer:
none of the given options is true
Step-by-step explanation:
Given: u=(-8,8) , v= (-1,2)
To find: vectors  such that
 such that 
Solution:
A vector is a quantity that has both magnitude and direction.

Let 
So,

So, u = 
So, none of the given options is true