Question

PLEASE HELP
Find an explicit rule for the nth term of the sequence.

-5, -25, -125, -625, ...

Answer 1

an = 5 • -5n
an = 5 • -5n + 1
an = -5 • 5n
an = -5 • 5n - 1

Answer 2

first term = -5
second term = -5 * 5
third term = -5 * 5^2
4th term = -5 * 5^3

can you see the pattern?

Answer 3

Yes as the terms increase so does the exponent

Answer 4

yes and if the term is 2 the exponent is 1
and if term is 3 the exponent is 2
for the first term the exponent is 0

Answer 5

Would it be C??

Answer 6

@welshfella

Answer 7

no because the n = exponent

Answer 8

That's the consistent pattern that's occurring, right

Answer 9

Oh

Answer 10

Ohhhh wait

Answer 11

its has to be c or d because of the -5

Answer 12

Can't it be B because of the continuous addition to the exponent as the terms increase?

Answer 13

no because the first term is -5 not 5

Answer 14

Then it must be C because the exponent is being subtracted from, correct?

Answer 15

*isn't

Answer 16

the way you have written the options is confusing
they should be

5 * (-5)^n

5 * (-5)^(n+1)

-5 * (5)^n

-5 * (5)^(n-1)

Answer 17

check out a

n = 1:- a 1 = first term = 5*(-5)^1 = -25

Answer 18

try d when n = 1

Answer 19

a1 = -5 * (5)^(1-1) = -5 ^ 5^0 = -5 * 1 = -5

Answer 20

* that should be -5 * 5^0

Answer 21

do you follow that ok?

Answer 22

Did you use D in your last problem?

Answer 23

a2 = -5*(5)^(2-1) = -5 * 5^1 = -5 * 5 = -25

Answer 24

yes

Answer 25

Would it be D then since the answer is -5?????

Answer 26

i used d for both calculations

Answer 27

*?

Answer 28

Oh I just saw it

Answer 29

Thank you so much

Answer 30

well you have to check a few not just the first
as you see it works for n = 1 and n = 2

Answer 31

Would you mind helping me with 2 more

Answer 32

normally i would but i gotta go right now

Answer 33

Oh alright. Thanks again!