X+3y=-5 4x-y=6 solve using elimination

 x+3y=-5

4x-y= 6

-4(x+3y=-5)

  4x-y=6

-4x-12y=20

4x-y=6                        the 4 y's will eliminate each other

0 -13y=26

-13y=26

y=26/-13

y=-2

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