Question

Find the first six terms of the sequence.

a1 = -8, an = 5 • an-1

Answer 1

please note that your sequence is a geometric progression whose first term is -8 and constant = 5. So your first six terms, are:
\[a _{1}=-8,a _{2}=-8*5=-40,a _{3}=-5*(-40)=-200\]

Answer 2

\[a _{4}=5*(-200)=-1000,a _{5}=5*(-1000)=-5000\]
\[a _{6}=5*(-5000)=-25000\]

Answer 3

oh wow, I get it now ... thank you !!!!!

Answer 4

can you help me on this one also , because it is different

Answer 5

Find an equation for the nth term of the arithmetic sequence.

8, 6, 4, 2, ...

Answer 6

in general, we have, for a generic n:
\[a _{n}=a _{1}*5^{(n-1)}\]

Answer 7

I have to make the equation myself now

Answer 8

would it be 8 + -2(n)

Answer 9

now, we have an arthmetic sequence, whose first term is 2, and constant=2, so your f n-term is:
\[a _{n}=a _{1}+(n-1)*c=2+(n-1)*2=2+2n-2=2n\]

Answer 10

sorry , ok I figured that one out myself ,

I have this question

Find the first six terms of the sequence.

a1 = -4, an = an-1 + 7

can you show me in steps how I can solve it I am a little confused

Answer 11

in this case you have an arithmetic sequence, whose first term is -4, and constant=7.
from your recurrence formula, I can write:
\[a _{2}=a _{1}+7=-4+7=3\]
\[a _{3}=a _{2}+7=3+7=10\]

Answer 12

\[a _{4}=a _{3}+7=10+7=17\]
finally:
\[a _{5}=a _{4}+7=17+7=24\]

Answer 13

but the answer choices are
an = -3 - 2
an = -3 + -2(n)
an = -3 + -2(n + 1)
an = -3 + -2(n - 1)

Answer 14

for generic nth term we have, applying the known formula about aruthmetic sequences:
\[a _{n}=a _{1}+(n-1)*c=-4+(n-1)*7=\]

Answer 15

is it c ?

Answer 16

\[=-4+7n-7=7n-11=a_{n}\]

Answer 17

that is not one of the choices :(

Answer 18

I see!

Answer 19

even if my formula is correct!

Answer 20

so what do I put

Answer 21

sorry, what is the meaning of: an = -3 + -2(n - 1)

Answer 22

maybe a number is missing between +sign and -sign?

Answer 23

it really means -3 + (-2)(n-1)

Answer 24

I'm very sorry, I don't know. Nevertheless I can say you that if your formulas, namely:
a1 = -4, an = an-1 + 7 are correct, then the expression for the n-th term is the one that I wrote above, namely:
a_n=7n-11