Substitution Property of Equality

Pronunciation: /ˈsʌb.stɪˌtu.ʃən ˈprɒp.ər.ti ʌv ɪˈkwɒl.ɪ.ti/ Explain

The substitution property of equality states that, if a = b, then b can be substituted for a in any equation without changing the truth value of the equation. For example:

  • Let a = b.
  • Let d = a + 2.
  • Then d = b + 2.


  1. McAdams, David E.. All Math Words Dictionary, substitution property of equality. 2nd Classroom edition 20150108-4799968. pg 172. Life is a Story Problem LLC. January 8, 2015. Buy the book
  2. substitution. Encyclopedia Britannica. Merriam-Webster. Last Accessed 12/13/2018. Buy the book

Cite this article as:

McAdams, David E. Substitution Property of Equality. 5/7/2019. All Math Words Encyclopedia. Life is a Story Problem LLC.

Revision History

5/7/2019: Changed equations and expressions to new format. (McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
5/5/2011: Removed broken links, updated license, implemented new markup. (McAdams, David E.)
12/24/2008: Added concept of 'truth value' of an equation. (McAdams, David E.)
7/1/2008: Initial version. (McAdams, David E.)

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