Question

HElp I will fan and medal!!!!!!!!!!!

Answer 1

what do u need help with?

Answer 2

Wat is S7 for 6-24+96-384+...?

Answer 3

ok.... so...

Answer 4

My choices are:
19,662
-78,642
-4,914
1,230

Answer 5

common ration is -4 .....did u get tht???

Answer 6

*ratio....
its a Geometric Series

Answer 7

ya I did

Answer 8

I ended up with -25644

Answer 9

S7 means the sum of first seven terms

Answer 10

?????

Answer 11

I dont understand how to do this I found the seventh term but I dont know the answer still

Answer 12

hold on first think in geometric series
\[a_n = a \times r^{n-1}\]
so
\[a_7 = 6 \times (-4)^6 = 24576\]

Answer 13

...okay

Answer 14

lol now jst forget it .....
sum of n terms in Geometric Series is
\[S_n = a \times \frac{ 1 - r^n }{ 1 - r }\]

Answer 15

uhhh okay

Answer 16

so
\[S_7 = 6 \times \frac{ (1 - (-4)^7) }{ 1 - (-4) }\]

Answer 17

now u can solve it ??? @SnowCrystal

Answer 18

\[6 \times \frac{ 5^7 }{ 5 }\]

Answer 19

what do I do next?

Answer 20

wht why 5^7????
its 1 - (-4)^7

Answer 21

1-(-4)^7 =5^7

Answer 22

\[S_7 = 6 \times \frac{ 1 - (-16384) }{ 5 }\]

Answer 23

@SnowCrystal howz tht possible.??? (no offense)

Answer 24

subtracting a negative makes the problem addition (none taken)

Answer 25

-24/6 =
96/-24 =
-384/96 =
see a pattern?

Answer 26

solve the equation i mentioned above
:))

Answer 27

how you have it set up it would be \[6 \times \frac{ 16385 }{ 5 }\]

Answer 28

and yes @silveralchemist09 it is -4

Answer 29

It's 1-(-4)^7 because you do the exponent first pEmdas

Then subtract 1 from that: pemdaS

Answer 30

∑n=176(−4)n−1=19662

Answer 31

6+6(−4)+6(−4)2+6(−4)3+6(−4)4+6(−4)5+6(−4)6=?

Answer 32

where did you get 176 from

Answer 33

@silveralchemist09 ??

Answer 34

WHTT???

Answer 35

i dont understand where @silveralchemist09 got 176 from

Answer 36

just forget it ....
solve the equation i mentioed :)
@SnowCrystal

Answer 37

so can u solve tht equation??

Answer 38

I did I got A for my answer

Answer 39

yup :)) good work :))

Answer 40

^_^ thanks