An infinite geometric series has a first term a1=15 and a sum of 45. Explain how you can use the formula S=a1/1-r to find the value of the common ratio. What is the value of r?

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step-by-step explanation:

since the sequence is geometric there is a common ratio r between consecutive terms, that is

r = 4 ÷ - 2 = - 2

r = - 8 ÷ 4 = - 2

r = 16 ÷ 8 = - 2

the next term - 13 must be incorrect as it should be - 32 for the sequence to be geometric.

the first 4 terms are therefore geometric with common ratio r = - 2

no he doesnt because "-16' is negatiive

step-by-step explanation:

srry ask agian

step-by-step explanation: