Given: AB = 95 miles (distance on the first day)
CD = 95 miles (distance on the third day)
To be proved: AB + BC = BC + CD
Statements:
- AB + BC = BC + CD (To be proved, as it is the statement to be shown equal)
- BC + AB = BC + CD (Communitive property of addition, from statement 3)
- AB + BC = CD + BC (Communitive property of addition, from statement 4)
- AB + BC = BC + CD (Transitive property of equality, from statements 3 and 5)
Hence, AB + BC is equal to BC + CD as proven in the two-column proof.