Write an equation for the nth term of each geometric sequence:
1) 2,-6,18,…
2) 5,10,20,…

see explanation

Step-by-step explanation:

The nth term of a geometric sequence is

= a₁

where a₁ is the first term and r the common ratio

(1)

a₁ = 2 and r = = = - 3 , then

= 2

(2)

a₁ = 5 and r = = 2 , then

= 5

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have

10 down (bang1)

5 up

5down (2)

2.5 up

2.5 down (3)

1.25 up

1.25 down (4)

now add them up : )

hoped i lol