Which sequences are geometric? Check all that apply.

–2, –4, –6, –8, –10, …
16, –8, 4, –2, 1
–15, –18, –21.6, –25.92, –31.104, …
4, 10.5, 17, 23.5, 30, …
625, 125, 25, 5, 1, …

The geometric sequences are:

16 , -8 , 4 , -2 , 1 ⇒ 2nd

-15 , -18 , -21.6 , -25.92 , -31.104, ⇒ 3rd

625 , 125 , 25 , 5 , 1 , ⇒ 5th

Step-by-step explanation:

In the geometric sequence there is a constant ratio between each two consecutive terms

Let us find which sequence has  a constant ratio between its consecutive terms

-2 , -4 , -6 , -8 , -10

∵ -4 ÷ -2 = 2

∵ -6 ÷ -4 = 1.5

- No constant ratio between the consecutive terms

∴ The sequence is not geometric

16 , -8 , 4 , -2 , 1

∵ -8 ÷ 16 = -0.5

∵ 4 ÷ -8 = -0.5

∵ -2 ÷ 4 = -0.5

∵ 1 ÷ -2 = -0.5

- There is a constant ratio -0.5 between the consecutive terms

∴ The sequence is geometric

-15 , -18 , -21.6 , -25.92 , -31.104,

∵ -18 ÷ -15 = 1.2

∵ -21.6 ÷ -18 = 1.2

∵ -25.92 ÷ -21.6 = 1.2

∵ 31.104 ÷ 25.92 = 1.2

- There is a constant ratio 1.2 between the consecutive terms

∴ The sequence is geometric

4 , 10.5 , 17 , 23.5 , 30,

∵ 10.5 ÷ 4 = 2.625

∵ 17 ÷ 10.5 = 1.619047619

- No constant ratio between the consecutive terms

∴ The sequence is not geometric

625 , 125 , 25 , 5 , 1 ,

∵ 125 ÷ 625 = 0.2

∵ 25 ÷ 125 = 0.2

∵ 5 ÷ 25 = 0.2

∵ 1 ÷ 5 = 0.2

- There is a constant ratio 0.2 between the consecutive terms

∴ The sequence is geometric

true? is that what you're asking or do you mean something else?

9) i can't see the angle so whatever it is just do this: cos(angle) x hypotenuse and then use that answer and they hypotenuse and plug it into this: (answer you just got)^2 + b^2 = (hypotenuse)^2. the first answer will be the answer of the adjacent side and the second answer after this equation will be the opposite side.

10) y = 14 x = √147 or 12.12435565

11) x = 4.8

12) x = 4.2

13) x = 9.3

14) pq: 13.2

qr : 17.6

angle p: 53º

15) angle c: 54.3º

angle a: 35.7º

16) h = 21040

v = 1841

step-by-step explanation:

10) 7/sin(30) = 14 = y

7^2 + b^2 = 14^2

49 + b^2 = 196

b^2 = 196 - 49

√b^2 = √147

x = √147

11) cos(70) x 14 = 4.788282007

x = 4.8

12) tan(25) x 9 = 4.196768923

x = 4.2

13) sin(31) x 18 = 9.270685348

x = 9.3

14) pq: sin(37) x 22 = 13.23993051

pq: 13.2

qr: cos(37) x 22 = 17.56998122

qr : 17.6

angle p: 180 - (37 + 90) = 53º

15) cos-1(7/12) = 54.31466529

angle c: 54.3º

angle a: 180 - (90 + 54.31466529) = 35.68533471

angle a: 35.7º

16) 4 x 5280 = 21120

cos(5) x 21120

h = 21039.63202

h = 21040

sin(5) x 21120

v = 1840.729287

v = 1841