We turn -5,12 into polar coordinates.  It's a Pythagorean Triple so 
r = 13   Ф=arctan(-12/5) + 180°   ( in the second quadrant )
so -5 = 13 cos Ф, 12 = 13 sin Ф
12 sin x - 5 cos x = 6.5
13 sinФ sin x + 13 cos Ф cos x = 6.5  
13 cos(x - Ф) = 6.5
cos(x - Ф) = 1/2
cos(x - Ф) = cos 60°
x - Ф = ± 60° + 360° k     integer k
x = Ф ± 60° + 360° k  
x = 180° + arctan(-12/5) ± 60° + 360° k  
That's the exact answer; 
x ≈  180° - 67.38° ± 60° + 360° k  
x ≈  122.62° ± 60° + 360° k   
x ≈  { 62.62°, 182.62°} + 360° k,  integer k
 
        
             
        
        
        
Answer:
x=-15, y=25. (-15, 25).
Step-by-step explanation:
2x+3y=45
x+y=10
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x=10-y
2(10-y)+3y=45
20-2y+3y=45
20+y=45
y=45-20
y=25
x+25=10
x=10-25
x=-15
 
        
                    
             
        
        
        
Answer:
B
Step-by-step explanation:
The volume is the height x area of base, 27pi / 3 = 9pi
Area of base is radius square x pi, 9 pi = 3^2 x pi
 
        
                    
             
        
        
        
Answer:
(7*100) can be written as 7*10^2
4 * / 100 i don’t know
if it was 4 * 100 then it’s 4*10^2
if it was divided then it’s 4*10^-2
8* 1/1000 = 8/1000 = 8*10^-3
add together to get 1.100008 * 10^3 (if it was 4*100)
or 7.00048 * 10^2 ( if it was 4/100)