ticket sale on Saturday night is triple the ticket sale on Friday night.
Therefore 
ticket sales on Saturday night = 3 x 12425 = 37275
Then
ticket sales for both nights = 12425 + 37275 = 49700
A ticket costs 35.
Let the number of people that attended the carnival on both nights be n.
Then, we have

Therefore 1420 people attended the carnival on both nights
 
        
             
        
        
        

Differentiate both sides with respect to <em>x</em>, assuming <em>y</em> = <em>y</em>(<em>x</em>).




Solve for d<em>y</em>/d<em>x</em> :



If <em>y</em> ≠ 0, we can write

At the point (1, 1), the derivative is

 
        
             
        
        
        
1/4 (8 + 6z + 12) 
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Combine like terms :
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1/4 (6z + 20)
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Apply distributive property :
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1/4(6z) + 1/4(20)
3/2z + 5
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Answer: 3/2z + 5
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