Question

calculați 2+2^2+2^3+...+2^2015
repede va rog

Answer 1

Răspuns:

Explicație pas cu pas:

S = 2+2^2+2^3+...+2^2015

2S = 2^2+2^3+...+2^2015 + 2^2016

2S - S = S

S = 2^2+2^3+...+2^2015 + 2^2016 - 2 - 2^2 - 2^3 - ... - 2^2015

= 2^2016 - 2

Answer 2

S=2+2²+2³+...+2²⁰¹⁵ |×2

2S=2²+2³+²4+...+2²⁰¹⁶

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2S-S=2²+2³+2⁴+...+2²⁰¹⁶-2-2²-2³-...-2²⁰¹⁵

S=2²⁰¹⁶-2