# How do you multiply matrices #A =((1, 2, 1), (-1, -1, 2), (-1, 1, -2))# and #B=((1, -1), (0, -1), (-1, 1))#?

##### 1 Answer

#### Explanation:

Before you can multiply matrices, you have to check that they are compatible, Matrices are named according to the number of rows (horizontal) and columns (vertical).

A is a

and B is a

This is only possible if the middle 2 numbers are the same

- in this case shown in

The answer will be a

Each ROW in A must be multiplied by each COLUMN in B.

This involves multiplying the elements in the row by the elements in B and adding them together to get a single answer.

This gives:

This gives

This gives

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This gives