Question

calculate the sum of the first five terms of a GP -2, 1/2, -1/8,1/32 and leave your answer correct to 2 significant figures
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Answer 1

Resposta:

S ≈ 1,60

Explicação passo a passo:

The ratio (r):

r = (1/2)/(-2) = -1/4

The 5th term: (1/32).(-1/4) = -1/128

GP (-2, 1/2, -1/8, 1/32, -1/128)

The sum (S):

S = -2 +1/2 -1/8 +1/32 -1/128

S =(-256+64-16+4-1)/128

S = -205/128 ≈ 1,60156...

S ≈ 1,60