Mathematics
jomana
15

If the sixth term of a sequence is 128 and the common ratio is 2, then what is the first term?

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(2) Answers
jasminemcdonald

first term = 4 second term = 4x2=8 3rd = 8x2 =16 4th = 16x2 = 32 5th = 32x2=64 6th = 64x2 = 128 answer: first term = 4

Genna57

common ratio mean geometric sequence [latex]a_n=a_1(r)^{n-1}[/latex] given tat r=2 and a6=128 [latex]a_6=a_1(2)^{6-1}=128[/latex] [latex]128=a_1(2)^{5}[/latex] [latex]128=a_1(32)[/latex] divide both sides by 32 [latex]4=a_1[/latex] the first term is 4

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