## mckenzieandjesus one year ago Find the common ratio of the sequence. –4, 8, –16, 32, . . . –2 –12 -1/-2 12

1. Nnesha

to find common ratio divide next term by the previous one $\large\rm r=\frac{ a_2 }{ a_1}~~or~~\frac{ a_3 }{ a_2}$a_2 = 2nd term a_3 = 3rd term

2. mckenzieandjesus

wouldnt the next term be 36?

3. mckenzieandjesus

i'm getting -9 but thats not right..

4. Nnesha

ratio between two numbers in geometric you will multiply the first by common ratio to get the nexxt one other way to solve for r is first term times r = 2nd term

5. Nnesha

$\huge\rm a_1 \times r = a_2$ what is first term and what is 2nd one ?

6. Nnesha

aww i see

7. mckenzieandjesus

-4 and 36

8. Nnesha

i see what u did there it's common ratio not common difference

9. Nnesha

now first one is -4 2nd term is what ?

10. Nnesha

1st term , 2nd term , 3rd, 4th term..........

11. mckenzieandjesus

32?

12. Nnesha

2 comes after 1 so what's 2nd term in this sequence –4, 8, –16, 32, . . .

13. mckenzieandjesus

8

14. Nnesha

right so $\huge\rm -4r=8$ solve for r

15. mckenzieandjesus

2?

16. Nnesha

hmm positive 8 divide by negative 4 = ?

17. mckenzieandjesus

-32

18. Nnesha

divide not multiply

19. mckenzieandjesus

ohh

20. mckenzieandjesus

-2!

21. Nnesha

to find common ratio we should divide 2nd term by first one or 3rd term divide by 2nd term

22. Nnesha

right yahoo!

23. mckenzieandjesus

so i gueesed the right answer then :) thanku

24. mckenzieandjesus

can u help me with another?

25. mckenzieandjesus

2, –10, 50, –250, . . .

26. Nnesha

will try

27. Nnesha

find common ratio ?

28. mckenzieandjesus

yes

29. Nnesha

alright same steps try it!

30. Nnesha

divide any term with the previous one you can divide 4th by 3rd one 3rd one by 2nd one 2nd one by first one