** Final Answer

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** Step-by-step Solution **

** Specify the solving method

We could not solve this problem by using the method: **Product of Binomials with Common Term**

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Multiply the single term $x-4$ by each term of the polynomial $\left(x+1\right)$

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Multiply the single term $x$ by each term of the polynomial $\left(x-4\right)$

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When multiplying two powers that have the same base ($x$), you can add the exponents

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Combining like terms $-4x$ and $x$

** Final Answer

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