Question: It cost Marci 20 cents to mail a postcard and 33 cents to mail a letter. She sent either a postcard or a letter to each of 18 people and spent $4.38 total.
Let x represent the number of postcards she wrote, and write an algebraic expression for:
a) The total cost in dollars of the postcards
b) The number of letters
c) The total cost in dollars of the letters
d) The sum of the costs in parts a and c is $6.00. write and solve an equation to determine the number of postcards marci mailed.