Question

What is the common difference of the following arithmetic sequence?
-4, -5.6, -7.2, -8.8,…

Answer 1

-1.6

Answer 2

thnks

Answer 3

no problem :)

Answer 4

What are the next 3 terms of the following sequence?
3, -1, -5, -9,…

Answer 5

What is the common difference of the following arithmetic sequence?
5, 4.5, 4, 3.5,…

Answer 6

-4 is common difference, so next three terms are :
-4 - 9 = - 13
-4 - 13 = - 17
- 4 - 17 = -21

common difference is -0.5

Answer 7

thnks so much... now what about this one What are the next 3 terms of the following sequence? 3, -1, -5, -9,…

Answer 8

already did it......next terms are -13, -17, -21

Answer 9

o ok..... didnt see it, thnks so much!

Answer 10

anytime

Answer 11

do you think you can help me with more

Answer 12

possibly

Answer 13

Find the three arithmetic means between -5 and -25.

Answer 14

Find S20 for the series -1 + -3 + -5 + -7 +…

Answer 15

-5 + 4d = -25
4d = -25 + 5
4d = -20
d = -5

-5, (-10, -15, -20), -25 <-- 3 terms are in parenthesis

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an = a1 + (n - 1) d
n = 20
a1 = -1
d = -2

a20 = -1 + (20 - 1) * -2
a20 = -1 + (19) * -2
a20 = -1 - 38
a20 = -39 <-- this is just the 20th term...not the sum
Be patient...I am getting there

sn = n(a1 + an)/2
n = 20
a1 = -1

s20 = 20(-1 + (-39) / 2
s20 = 20 (-40) / 2
s20 = - 800/2
s20 = -400 <-- this is the sum

Answer 16

thks.. you are great! ima give you more

Answer 17

Find the 6th term of the sequence with t1 = -4 and tn = 5tn-1.

Answer 18

Find S8 for the series -2 + -10 + -50 + -250 +…