Question

• What is the sum of the geometric sequence 8, –16, 32 … if there are 15 terms

Answer 1

8, -16, 32, -64, 128, -256, 512, -1024, 2048, -4096, 8192, -16384, 32768. -65536, 131072.

87384 is the sum.

Answer 2

\[Sum _{n}=\frac{a _{1}(1-r ^{n})}{1-r}\]

Answer 3

\[=\frac{8(1-(-2)^{15}}{1-(-2)}\]

Answer 4

87384

Answer 5

8(3)^15/3 = 24^15/3?

Answer 6

No. Remember the rule...powers first

Answer 7

\[\frac{8(1-(-32768))}{3}\]

Answer 8

\[\frac{8(32769)}{3}\]

Answer 9

\[\frac{262152}{3}\]

Answer 10

\[87384\]

Answer 11

ooh thank u so much

Answer 12

yw