Make p the subject of the formula
y = 3p2 - 4

p =√(y+4)/3

Step-by-step explanation:

y=3p^2-4

so 3p^2=y+4

then p^2=(y+4)/3

so p =√(y+4)/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