Answer:
9.
1. Given
2. Multiplication Property of Equality
3. RS + ST = RT
4. Addition Property of Equality
5. RS is not equal to RT because RS is 1/2 half of RT
6. S is the Midpoint
10.
1. Given
2. LM = MN
3. Given
4. Definition of Midpoint
5. Transitive Property
6. LM = MO