Over the past week, 40% of the phone calls to Alicia's cell phone were from her son. Let's say you know that her son called her 12 times. Find out how many total calls she received.

72 is the answer to this problem

for this case we must apply distributive property to the following expression:

the distributive property states that:

then, when applying the property we have to multiply the -2 for each term within the parenthesis: