The first term of a certain sequence is -2 and the second term is -4. Every term after the second term is obtained by dividing the sum of the previous two terms by 2. For example, the third term of the sequence is (-4)+ (-2)/2=-3. What is the sixth term of this sequence?

A) -3

B) -27/8

C) -21/8

D) -7/4

E) -1/8

List the terms:

  1. –4 (given)
  2. –2 (given)
  3. –3 (given, but also \frac{-4+(-2)}{2})
  4. –2.5 (\frac{-2+(-3)}{2})
  5. –2.75 (\frac{-3+(-2.5)}{2})
  6. –2.625 (\frac{-2.5+(-2.75)}{2})

Put that in your calculator and convert it to a fraction:

-2.625 = -\dfrac{21}{8}

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