In a geometric progression, the first tern is 81 and the fourth term is 24. find the common ratio​

Question

In a geometric progression, the first tern is 81 and the fourth term is 24. find the common ratio​

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Thu Thảo 3 years 2021-07-31T09:35:06+00:00 2 Answers 140 views 0

Answers ( )

  1. trucchi
    0
    2021-07-31T09:37:04+00:00
    Reply

    Hello,

    Let’s say a the  first term and r the ratio  of the G.P.

    u_1=a=81\\u_2=a*r\\u_3=a*r^2\\u_4=a*r^3\\\\\dfrac{u_4}{u_1} =\dfrac{a*r^3}{a} =r^3=\dfrac{24}{81} =\dfrac{8}{27} \\\\r=\sqrt[3]{\dfrac{8}{27} } \\\\\boxed{r=\dfrac{2}{3}}\\

  2. Thunguyet
    0
    2021-07-31T09:37:04+00:00
    Reply

    Step-by-step explanation:

    81/24

    = 27/8

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