Need help quick

 

What is the coefficient of x in (x^3 + x^2 + x + 1)(x^4 + 3x^3 + 4x^2 + 8x + 7)?     

 

Every term in one is to be multiplied by every term in the other.  

Consider only the pairs of terms that result in x with a coefficient.     

 

                       (x³ + x² + x + 1) • (x⁴ + 3x³ + 4x² + 8x + 7)    ==>>  7x    

                       (x³ + x² + x + 1) • (x⁴ + 3x³ + 4x² + 8x + 7)    ==>>  8x    

                                                                                           total   15x    

                       The coefficient of x is 15.   

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