prisylillinb
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The first term of a geometric sequence is 7, and the ratio (multiplier) is 3. what is the sum of the first 5 terms of the sequence? user: what is the 8th term of this geometric sequence? 6, 48, 384, 3072, . . .

Respuesta :

caylus
Hello,

1)
[tex] a_{1}=7 [/tex]
[tex] a_{2}=7*3 [/tex]
[tex] a_{3}=7*3^2 [/tex]

[tex] a_{n}=7*3^{n-1} [/tex]

[tex] s=a_{1}+a_{2}+a_{3}+a_{4}+a_{5}=7*(1+3^1+3^2+3^3+3^4) [/tex]
[tex] =7*\frac{3^{5}-1}{3-1} [/tex]
[tex] =7*242/2=847 [/tex]

2)
[tex] b_{8}=6*8^{8-1}=12582912 [/tex]




















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