Word problem.. i need help. Due at midnight

The Brady family received 1 letter on July 28.

Step-by-step explanation:

Step 1:

Assume a = the number of letters, b = the number of bills, c = the number of ads, and d = the number of magazines.

From the question, they got 15 pieces of mail that day so

They got 5 more magazines than bills so

The got the same number of letters as ads so

They got 3 more bills than ads so

Step 2:

As we have only one equation to solve the values, we need to make every term in terms of a single term.

We make everything in terms of c.

So

Substituting all this in the equation, we get

Step 3:

Substituting c = 1 in other terms, we get

and

As a = 1, they received 1 letter that day.