Answer:

Step-by-step explanation:
Given

Required
Determine the expression for s
The speed is calculated as:

Substitute S for speed

Let the number of books be b and the time be m.
The expression becomes

Hence, the expression for the scenario is:

 
        
             
        
        
        
(6x-18)(x+4)/(3x-9)=6(x-3)(x+4)/3(x-3)=2(x+4)=2x+8
        
             
        
        
        
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