compute each matrix sum or product if it is defined. If an expression is undefined, explain why. Let
![1358_3433df26-c464-4ae3-80fe-df83d134c8cc.png](https://secure.tutorsglobe.com/CMSImages/1358_3433df26-c464-4ae3-80fe-df83d134c8cc.png)
In the rest of this exercise set and in those to follow, assume that each matrix expression is defined. That is, the sizes of the matrices (and vectors) involved "match" appropriately