Question

If the sixth term of a sequence is 128 and the common ratio is 2, then what is the first term?


1
2
4


i think 2 but not shure

Answer 1

an = a(r)^(n-1)

Answer 2

um wat ?

Answer 3

.hi im ur fann !!!

Answer 4

well you know n = 6, an = 128 and r = 2

so you have

\[128 = a \times (2)^{6 -1}\]

or

\[128 = a \times 2^5\]

just solve for a

Answer 5

which is the 1st term

Answer 6

so a=4 ????????????

Answer 7

well that seems to work

2^5 = 32

and 32 x 4 = 128

well done