Finally let A B and C be 2 Times 2 matrices over a commutati

Finally, let A, B and C be 2 Times 2 matrices over a commutative ring with identity. 1. Show that (A+B)+C = A+(B+C).

Solution

finally,let A,B and C be 2 x 2 matrices over a commutative ring with identity

1. show that (A+B)+C=A+(B+C)

this is true

A unit ring is a ring with multiplicative identity. it is therefore sometimes also known as a ring with identity