Mrs. Treacher has weekly quizzes for the students in her math class. She wants to add a litle fun to the weekly quiz by giving her students the chance to win bonus points on each week's quiz. She has three bags filled with pieces of paper. In the first bag, the pieces of paper have different
shapes drawn on them. In the second bag, the pieces of paper have different numbers written on them. In the third bag, each piece of paper has
a different color written on it. She wants there to be 4 fewer pieces of paper in the shapes bag than in the numbers bag and 9 more pieces of
paper in the color bag than in the number bag.
At the beginning of the semester, each student takes a turn randomly selecting a piece of paper from each bag, writes down the results, and
replaces the pieces of paper. Before each quiz, Mrs. Treacher randomly draws a piece of paper from each bag. If her choices match those of one
of the students, they get bonus points on the quiz.
Part A
If x is the number of pieces of paper in the numbers bag, write an expression to model the number of pieces of paper in each bag.