Using binomial theorem, expand each of the following:

(3x + 2y)5


To find: Expansion of (3x + 2y)5


Formula used: (i)


(ii) (a+b)n = nC0an + nC1an-1b + nC2an-2b2 + …… +nCn-1abn-1 + nCnbn


We have, (3x + 2y)5


[5C0(3x)5-0] + [5C1(3x)5-1(2y)1] + [5C2(3x)5-2(2y)2] + [5C3(3x)5-3(2y)3]+ [5C4(3x)5-4(2y)4] + [5C5(2y)5]



[1(243x5)] + [5(81x4)(2y)] + [10(27x3)(4y2)] + [10(9x2)(8y3)] + [5(3x)(16y4)] + [1(32y5)]


243x5 + 810x4y + 1080x3y2 + 720x2y3 + 240xy4 + 32y5


Ans) 243x5 + 810x4y + 1080x3y2 + 720x2y3 + 240xy4 + 32y5


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