The sum of the series \[1+2x+3{{x}^{2}}+4{{x}^{3}}+.........\]upto \[n\] terms is

\[\frac{1-(n+1){{x}^{n}}+n{{x}^{n+1}}}{{{(1-x)}^{2}}}\]

The sum of the series \[1+2x+3{{x}^{2}}+4{{x}^{3}}+.........\]upto \[n

1.	The sum of the series \[1+2x+3{{x}^{2}}+4{{x}^{3}}+.........\]upto \[n\] terms is
A.	\[\frac{1-(n+1){{x}^{n}}+n{{x}^{n+1}}}{{{(1-x)}^{2}}}\]
B.	\[\frac{1-{{x}^{n}}}{1-x}\]
C.	\[{{x}^{n+1}}\]
D.	None of these
Answer» B. \[\frac{1-{{x}^{n}}}{1-x}\]

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The sum of the series \[1+2x+3{{x}^{2}}+4{{x}^{3}}+.........\]upto \[n\] terms is

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