Is the following sequence arithmetic? if so, identify the common difference. -0.3, 0.1, 0.5, 0.9, … a) yes; -0.2 b) no c) yes; -0.4 d) yes; 0.4

Option D

Yes 0.4

Step-by-step explanation:

A sequence is said to be arithmetic if there is a pattern as

nth term is got by adding d to n-1th term.

d = common difference

The sequence will look like

a, a+d,a+2d, a+3d,

where I term= a and each time d is added to get the next term.

Our given sequence is

-0.3, 0.1, 0.5, 0.9, …

Let us find difference between Ii and I term

=0.1-(-0.3) = 0.4

Similarly iii term - ii term

=0.5-0.1 =0.4

and iv term - iii term = 0.9-0.5 = 0.4

Hence confirmed that this is an arithmetic sequence with I term =-0.3 and common difference = 0.4

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads