Which of the following shows an equivalent expression to
[(5.3). 12] if only the associative property was used to transform the expression?

The equivalent expression using associative property is

Given expression is [(5.3). 12]

We are asked to write a equivalent expression using associative property

The associative property states that you can add or multiply regardless of how the numbers are grouped. By 'grouped' we mean 'how you use parenthesis'. In other words, if you are adding or multiplying it does not matter where you put the parenthesis

Associative property is as follow:-

a + (b + c) = (a + b) + c   { for Addition}

(a x b) x c = a x (b x c)  { for multiplication}

The given expression is [(5.3). 12], which can be written as

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