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If 2 + 2^2 + 2^3 +...+ 2^n = 510 then n = ?

User Karl Brown
by
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2 Answers

4 votes

Answer:

N= 8

Explanation:

User Quest
by
3.4k points
2 votes

Answer:

n = 8

Explanation:

This Geometric series. r = 2 and a = 2


S_(n)= (a(r^(n)-1))/(r-1)\\\\\\(2(2^(n)-1))/(2-1)=510\\\\(2*(2^(n)-1))/(1)=510\\\\2*(2^(n)-1) = 510\\\\2^(n-1)=(510)/(2)\\\\2^(n) - 1 = 255\\\\2^(n)=255+1\\\\2^(n) = 256\\\\2^(n) =2^(8)

n = 8

User Shay Rybak
by
3.0k points