What is the explicit formula for this geometric sequence? 8, 4, 2, 1

  a[n] = 2^(4-n)

Step-by-step explanation:

There are many ways the formula for the given sequence can be written. The first term (a[1]) is 8 and the common ratio (r) is 1/2, so the generic form is ...

  a[n] = a[1]·r^(n-1)

  a[n] = 8·(1/2)^(n-1)

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If we recognize that 8 = 2^3 and 1/2 = 2^-1, then we can write this as ...

  a[n] = 2^3·(2^-1)^(n-1) = 2^(3 -n +1)

  a[n] = 2^(4 -n)

in the math equation 8 x 7 = 56, the 8 and the 7 are both factors of 56, since in this lesson we will use square tiles to figure out the factors of a whole find as many different arrays as you can, but follow one important rule: all the rows must have the i can make two rows of nine, so 2 and 9 are both factors of 18.

step-by-step explanation: