HELP!!!! What is the 8th term of the geometric sequence 4, -20, 100, ...?

Question

parthkohli · Answer

Basically, in a geometric sequence,$$A_n = A_1 \times r^{n - 1}$$

parthkohli · Answer

Can you find the ratio, a.k.a $r$?

anonymous · Answer

i dont know how to do that

anonymous · Answer

-312,500
	-12,500
	62,500
	1,562,500
these are the possible answers

anonymous · Answer

is it 62,500?

anonymous · Answer

use ar^{n-1} n is the last term of the sequence here value of n is 8. so put the value of n = 8 and a is your first term put a = 4. Common ratio that axr / a that means dividing next term by previous one you get this ratio here ratio is -5. So, solve this you get your answer

anonymous · Answer

is it -12,500? i just did what you said and thats what i got

anonymous · Answer

I got this
−312,500