The coefficient of x3 in the expansion of (1+x)3(2+x2)10 is.A. 214...

The coefficient of x3 in the expansion of (1+x)3(2+x2)10 is.

A. 214

B. 31

C. (3/3)+(10/1)

D.(3/3)(10/1)29

1Comment
Rohit Panwar @panwarrohit
19 Nov 2019 07:11 pm

@sandeep first of all we need to expend (1+x)3 which is

(1+x)3 =1+3x+3x2+x3

now expension of (2+x2)10 is

210+10*29.x2+45*28.x4-------------------------

now we have to find coefficient of x3  which we will get by multiply each terms and avoid all the terms which go beyond x3.

therefor we get,

29(2+3*10)

=214

option A will be correct

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