I am reading T. Y. Lam's book, "A First Course in Noncommutative Rings" (Second Edition) and am currently focussed on Section 1:Basic Terminology and Examples ...(adsbygoogle = window.adsbygoogle || []).push({});

I need help with yet another aspect of Example 1.14 ... ...

Example 1.14 reads as follows:

Near the end of the above text from T. Y. Lam we read the following:

" ... ... Moreover ##R \oplus M## and ##M \oplus S## are both ideals of ##A##, with ##A / (R \oplus M ) \cong S## and ##A / ( M \oplus S ) \cong R## ... ... "

Can someone please help me to show, formally and rigorously that ##A / (R \oplus M ) \cong S## and ##A / ( M \oplus S ) \cong R## ... ...

My only thought so far is that the First Isomorphism Theorem for Rings may be useful ...

Hope someone can help ... ...

Peter

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# I Triangular Matrix RIngs ... Another Question

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**