** Final Answer

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** Step-by-step Solution **

** Specify the solving method

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Apply the product rule for differentiation: $(f\cdot g)'=f'\cdot g+f\cdot g'$, where $f=x+1$ and $g=x-4$

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The derivative of a sum of two or more functions is the sum of the derivatives of each function

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The derivative of a sum of two or more functions is the sum of the derivatives of each function

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The derivative of the constant function ($1$) is equal to zero

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The derivative of the constant function ($-4$) is equal to zero

The derivative of the linear function is equal to $1$

Any expression multiplied by $1$ is equal to itself

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The derivative of the linear function is equal to $1$

The derivative of the linear function is equal to $1$

Any expression multiplied by $1$ is equal to itself

The derivative of the linear function is equal to $1$

Any expression multiplied by $1$ is equal to itself

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The derivative of the linear function is equal to $1$

** Final Answer

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