Find the values of s1 and r for a geometric sequence with s4 = 18 and s6= 8

  see below

Step-by-step explanation:

The ratio of terms that are two terms apart (s4 and s6) is the square of the common ratio:

  s6/s4 = r^2

  r = √(8/18)

  r = 2/3 . . . . . matches choices A and C

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Using the formula for the general term, we now know enough to find the first term:

  sn = s1·r^(n-1)

  s4 = s1·(2/3)^(4-1)

Using s4 = 18 and multiplying by (2/3)^-3, we get ...

  18·(2/3)^-3 = s1 = 18·27/8

  s1 = 243/4 . . . . . matches choice A

fist on the left goes with the third on the right. second on the left goes with the fourth on the right. third on the left goes with the second on the right. the fourth on the left goes with first on the right