15) What is the value of y?
(4y - 9)
40
5yº

angle1 = 4y - 9°

angle2 = 40°

angle3 = 5y°

Angle sum property

180° = angle1 + angle2 + angle3

Therefore,

180 = (4y - 9) + 40 + 5y

180 = 4y - 9 + 40 + 5y

180 = 9y + 31

180 - 31 = 9y

149 = 9y

149/9 = y

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

you didn't post any answer choices, so its not 100% clear what your teacher is looking for

however, log(15/7) is equivalent to log(15) - log(7)

i'm using the rule log(x/y) = log(x) - log(y)