Diketahui barisan geometri 4,12,36tentukanA=U6B=S6​

Jawaban:

A. U6

Un = a × r^n-1

U6 = 4 × 3^6-1

U6 = 4 × 3^5

U6 = 4 × 243

U6 = 972

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B. S6

Sn = a × ( r^n – 1 ) / r – 1

S6 = 4 × ( 3^6 – 1 ) / 3 – 1

S6 = 4 × ( 729 – 1 ) / 2

S6 = 4 × 728 / 2

S6 = 2.912 / 2

S6 = 1.456

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