Answer:36cm
Step-by-step explanation:
 
        
             
        
        
        
Answer: use google calculator It’s reliable
Step-by-step explanation:
 
        
                    
             
        
        
        
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a ) Two matrices cannot be multiplied.
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b ) 
The answer is | 20 - 4 - 12 |     
   |   8 2 19 - |
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The answer is 42.80 , 2.28 is what they saved and i got the .80 cents because i rounded up from .78