Answer:
 It's (very roughly) 12 hours from one high tide to the next, and of course the same for low tides. That's because the tides produced when the Moon is directly overhead or in the opposite direction are the same. Same with two low tides, since there are two tides a day (both low and high).
 
        
                    
             
        
        
        
Answer:
Following are the solution to this question:
Step-by-step explanation:
Please find the complete question in the attached file.
In the given equation, when the point t=0 
So, 

            
The value of the coordinates are  . so, the equation of the line is:
. so, the equation of the line is: 
 
 
 
        
             
        
        
        
H is the answer 
 and the line of the symmetry is like the picture
 
        
        
        
Answer:
6 1/6
Step-by-step explanation:
-2 1/2 * 3 1/3
-2 * -3 = 6
1/2 * 1/3 = 1/6
 
        
             
        
        
        
The answer for:
20) 
6x-7+6x³-4x-10x³-4-8x - 2x²= −43−22−6−11
19)
8u+6+7u+(-10) + (-5u) + 8= 10+4