# equality

In mathematics, equality is when two or more expressions which mean the same thing. Thus 3 + 4 = 7 is an
equality. For constant nonzero *a*, *b*, *c*, the equality *a* = *b* implies:

*b* = *a*

*a* + *c* = *b* + *c*

*ac* = *bc*

and if *b* = *c* then *a* = *c*. See also equivalence.