Answer: 
1. C. cylindrical coordinates 
2 A. spherical coordinates 
3. A. spherical coordinates
4. D. Cartesian coordinates
5  B. polar coordinates 
Step-by-step explanation:
USE THE BOUNDARY INTERVALS TO IDENTIFY
1. ∭E dV where E is:  
x^2 + y^2 + z^2<= 4, x>= 0, y>= 0, z>= 0  -- This is A CYLINDRICAL COORDINATES SINCE x>= 0, y>= 0, z>= 0 
2. ∭E z^2 dV where E is:  
-2 <= z <= 2,1 <= x^ 2 + y^2 <= 2 This is A SPHERICAL COORDINATES
3. ∭E z dV where E is:
1 <= x <= 2, 3<= y <= 4,5 <= z <= 6 -- This is A SPHERICAL COORDINATES
4. ∫10∫y^20 1/x dx  ---- This is A CARTESIAN COORDINATES
5. ∬D 1/x^2 + y^2 dA where D is: x^2 + y^2 <=4  This is A POLAR COORDINATES
 
        
             
        
        
        
Answer:
(2,-3)
Step-by-step explanation:
I am not sure if you meant the first equation to be y or -y.  I solved it as y.
y = x-5                       -x -3y =7
I am going to take the second equation and write it as x =
-x - 3y = 7  Give equation
-x = 3y +7   Add 3y to both sides
x = -3y-7  Multiplied each term in the equation by -1 so that x could be positive
I am going to substitute -3y-7 for x in the first equation up above
y = x - 5
y = -3y -7 - 5  Substitute -3y-7 for x
y = -3y -12  Combined -7-5
4y = -12  Added 3y to both sides
y = -3  Divided both sides by 4.
I now know that y is -3, I will plug that into x = -3y-7 to solve for x
x = -3(-3) -7
x = 9-7   A negative times a negative is a positive
x = 2
 
        
             
        
        
        
Answer:
They are both acute angles 
 
        
                    
             
        
        
        
I found 37.4 m.
I tried using trigonometry and the tangent of an angle (in this case 39°):