Name the property that justifies each statement

Question

1. mABC = mDEF and mDEF = mABC

2. AB = CD, CD = EF. therefore, AB = EF. 

3. x + 7 = 5; x + 7 - 7 = 5

4. X = y; if x = 18, then y = 18

5. A = A

Answer 1

1. The Symmetric Property (http://www.mathwords.com/s/symmetric_property.htm)

2. The Transitive Property (http://www.mathwords.com/t/transitive_property.htm)

3. false. However, assuming you meant to write:

x + 7 = 5; x + 7 - 7 = 5 - 7; x = -2

 

Then the property which would justify that would be the additive property

(http://www.mathwords.com/a/additive_property_of_equality.htm)

4. Substitution property (http://www.allmathwords.org/en/s/substitutionpropofequality.html)

5. Reflexive property (http://www.mathwords.com/r/reflexive_property.htm)