Answer:
2) 11 
3) 21 
4) 7 
Step-by-step explanation:
2) (-6) -(-17) = 17 - 6 = 11 
3) 19 - (-2) = 19 + 2 = 21 
4) (-13) + 20 = 20 - 13 = 7
 
        
             
        
        
        
Start by decomposing the number inside the root into primes 
Then group the terms into cubes if possible 

rewrite the root
![\sqrt[3]{80}=\sqrt[3]{10\cdot2^3}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B80%7D%3D%5Csqrt%5B3%5D%7B10%5Ccdot2%5E3%7D)
then cancel the terms that are cubes and bring them out of the root 
![\sqrt[3]{80}=2\sqrt[3]{10}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B80%7D%3D2%5Csqrt%5B3%5D%7B10%7D) 
 
        
             
        
        
        
Answer:
79 inches 
Step-by-step explanation:
1 foot equals 12 inches
6 feet = 6*12 = 72 inches
72+7=79
79 inches 
 
        
             
        
        
        
I first think that you need to do 64 squared which is 8 then add the other 8 then you have 16 then do 16 square which equals 4 then I think you do 4 x 3 then add 25 then you get your answer..... hopefully
        
             
        
        
        
Answer: the the 2nd circular one
Step-by-step explanation: Functions can't just go in a circle, they will repeat the x value