We have,
(441+561)120
Tr+1=Cr120(441)120−r(5)6r
⇒Tr+1=Cr120(2)2120−r(5)6r
For rational terms r=6λ,0≤r≤120, hence
r=0,6,12,...,120
So, total number of rational terms are 21.
JEE Main 2021 — Mathematics Algebra
The number of rational terms in the binomial expansion of (441+561)120is_______.
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