PLEASE HELP!!!!!!!!
What is the 8th term of this sequence? 1,-1/2,1/4,-1/8
1 answer:
This is a geometric sequence with first term 1 and common ratio -1/2. r=-1/2.
a(n) = a(1)*(r)^(n-1).
Check: If n=2 our formula must return -1/2. Does it?
a(2) = 1(-1/2)^(2-1) = (-1/2)^1 = - 1/2. Yes.
a(3) should be 1/4. Is it? a(3) = (-1/2)^(3-1) = 1/4 Yes.
Then a(8) = (-1/2)^(8-1) = (-1/2)^7 = -1 / 2^7 = -1/128 (answer)
You might be interested in
Six billion three hundred ninety-two million ninety-four thousand and three
First, we have to find the rate:
500/50
100/10
10/1
10 cents a pitch:
129 * 10 = 1290
It will cost $12.90
100%-30%=70%
100%+30%=130%
to decrese by 30%, multiply by 70%
to increase by 30%, multiply by 130%
