Solving two step equations:15a-54=-9

15a - 54 = -9. Add 54 to each side.

15a = 45. Divide each side by 15.

a = 3

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