2 + 22 + 23 + ... + 29 =?

This is a G.P. in which a = 2, r = 22 = 2 and n = 9. 2 ∴Sn = a(rn - 1) = 2 x (29 - 1) = 2 x (512 - 1) = 2 x 511 = 1022. (r - 1) (2 - 1)

Correct Answer: 1022

Explanation:

This is a G.P. in which a = 2, r =	2²	= 2 and n = 9.
	2

∴S_n =	a(rⁿ - 1)	=	2 x (2⁹ - 1)	= 2 x (512 - 1) = 2 x 511 = 1022.
	(r - 1)		(2 - 1)

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