Q29 of 70 Page 371

Find the coefficient of x in the expansion of (1 – 3x + 7x2) (1 – x)16.

To Find : coefficient of x


Formula :


We have a formula,



Therefore, expansion of (1-x)16 is given by,





Now,



Multiplying the second bracket by 1 , (-3x) and 7x2



In the above equation terms containing x are


and -3x


Therefore, the coefficient of x in the above expansion



=-16-3


=-19


Conclusion : coefficient of x =-19


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