Question

7. Find the formula for the 17th term of the sequence in which a1 = -3 and the common ratio is -2.
-2 • (-3)^16 -3 • (-2)^16
-3 • (-2)^17 -2 • (-3)^17
8. Find the formula for the 14th term of the sequence in which a1 = 2 and the common ratio is -4.
-4 • 2^13 2 • (-4)^13
2 • (-4)^14 -4 • 2^14
9. Find the formula for the 17th term of the sequence in which a1 = -2 and the common ratio is -3.
-3 • (-2)^16 -3 • (-2)^17
-2 • (-3)^16 -2 • (-3)^17

Answer 1

What are you thinking here?

Answer 2

i honestly dont know. all the other questions were sequences like 1,4,7,10 so you add 3 to each number then it says find the 24 number. which i understand. this one i just dont really understand what it is asking for

Answer 3

Do you remember the formula for geometric sequences?

Answer 4

uhm i think it is an = a1r ^n-1

Answer 5

That is right. Now remember what a1, r, and n mean. It's just substitution.

Answer 6

not really :/

Answer 7

a1 is the first term. r is the common ratio. n is the number of the term you want to find out about.

Answer 8

hm okay i still dont understand how i would plug all that in and get any of those crazy answers

Answer 9

Look at (7). a1 = -3, so we need an expression that starts with -3. Since the ratio is -2 we need an expression where -2 is being raised to a power. Since we are looking for term 17 we need to look for an expression where the exponent is 17-1 (16). Put all together we get answer........

Answer 10

so its -3 • (-2)^16

Answer 11

True. What about the other two problems?

Answer 12

2 • (-4)^13 is number eight and and number nine is -2 • (-3)^16

Answer 13

8 - ]

Answer 14

thank you so muchhh!!