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Home  >>  CBSE XI  >>  Math  >>  Binomial Theorem

Prove that $\sum\limits_{r=0}^n 3^{r-n}C_r=4^n$

1 Answer

$\sum\limits_{r=0}^n 3^rnC_r=nC_0+nC_1.3^1+nC_23^2+.......+nC_3.3^r+......nC_n.3^n$
$\Rightarrow (1+3)^4$
$\Rightarrow 4^n$
Hence proved.
answered Jun 23, 2014 by sreemathi.v
 
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