### Home > CCA2 > Chapter 9 > Lesson 9.1.1 > Problem 9-15

9-15.

Joanne was making repairs to her deck and needed to buy some supplies. She purchased two posts, three boards, and four piers for

Define variables for the number of posts, boards, and piers.

Write three equations with the three unknowns.

First Equation:

If # of posts;

*# of boards;*

*# of piers, then*

Solve.