Hello, I've tried these problems out already, I'm just a little stuck. I appreciate all your help. Thanks.
(Also, if you can explain how you came up with the answer, that would also be great so that I can learn), Thanks much.
1.
What is the sum of the first eight terms of the series?
(−500)+(−100)+(−20)+(−4)+(−0.8)+...
Round the answer to two decimal places if necessary.
−996.09
−625
−624.99
−623
2.
What is the sum of the first 7 terms of the series −3+6−12+24−... ?
+128475 1. First eight terms ..... (−500)+(−100)+(−20)+(−4)+(−0.8)+...
The common ratio is (1/5)....the sum, S, is given by :
S = First Term [ 1 - common ratio^8] / [ 1 - common ratio ] =
S = -500 [ 1 - (1/5)^8] / [ 1 - 1/5] = -[ 624 + 624/625 ] ≈ -624.99
2. What is the sum of the first 7 terms of the series −3+6−12+24−... ?
The common ratio is -2
The sum, S, is given by :
S = -3 [ 1 - (-2)^7 ] / [ 1 - (-2) ] = -129
