Maria thinks of a number double it and add 5 answer is 21 write as an equation in X and solve it to find Maria's number​

The number is 8

Step-by-step explanation:

2x +5 =21

2x= 21-5

2x=16

2x/2=16/2

x=8

To check

8×2=16

16+5=21

true

step-by-step explanation:

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