Answer:
8 rabbits
22 chickens
Step-by-step explanation:
c = chickens
r = rabbits
heads - c + r = 30
legs - 2c + 4r = 76
We can now use these two equations to create one by isolating the variable (c) in the first equation. 
c = 30 - r
2c + 4r = 76
2(30 - r) + 4r = 76 
60 - 2r + 4r = 76
2r = 16
r = 8 
Now we know that there are 8 rabbits, which means that there has to be 22 chickens in order to have 30 heads. 
 
        
             
        
        
        
        
Answer:
The table of Henry's family will be at (4, -4)
Step-by-step explanation:
The problem states that the initial coordinates of Henry's family is at the coordinates (-4, 4). Each 15 minutes the restaurant will rotate 90° every 15 minutes. If we follow the Cartesian plane and the center of the restaurant being at (0, 0) we know that the table will be situated at the (4, 4) coordinates of the restaurant after the first rotation. After the 30 minute mark, the restaurant rotates one more time and moves the table of Henry's family at the (4, -4) coordinates of the restaurant as the center of the restaurant will never move.