6. In the diagram below, it is given that points A, B, C, and D are all collinear and AD=CB. Fill in the blanks of the reason column to justify each step in proving that AC = DB [4 points]
A
с
D
B
Statement
Reason
1. AD = CB
1. Given
2.
2. AD = AC + CD
CB = CD + DB
3. AC + CD = CD + DB
3.
4. CD= CD
4.
5. AC = DB
5.