1. Homework 2-2 #14 M I L D Step 1. MI = LD 2. IL = IL
3. MI + IL = LD + IL
4. MI + IL = ML; LD + IL = ID
5. ML = ID
Reason
1. Given
2. Reflexive Property
3. Addition Property
4. Segment Addition Postulate
5. Substitution

2. 2-2 PROOFS

3. Proof I will give you the 1st step First reason is always “given” STEP
1. 3x = 7 – 1/2x
2. 6x = 14 – x
3. 7x = 14
4. x = 2
REASON
1. GIVEN
2. Multiplication Property
3. Addition Property
4. Division Property

4. TOO: 3 Steps Step 1. 2x + 3 = 11 2. 2x = 8 3. x = 4 Reason 1. Given
2. Subtraction Property
3. Division Property

5. Example: Geometry Proof
Given: RS = PS and ST = SQ
Prove: RT = PQ S Q T
Step
1. RS = PS, ST = SQ
2. RS + ST = PS + SQ
3. RS + ST = RT
PS + SQ = PQ
4. RT = PQ
Reason
1. Given
2. Addition Property
3. Segment Addition Postulate
4. Substitution

6. TOO: 5 Step Proof A B Given: Prove: C O D Step 1. 2. 3. 4. 5. Reason
2. Angle Addition Postulate
3. Substitution Property
4. Reflexive Property
5. Subtraction Property

7. Homework Page 41 #1-14 Flash Cards #11-14 are each 4 step proofs
Reflexive Property
Substitution