# How do you multiply #((1, -3, 2), (2, 1, -3), (4, -3, -1))# and #((1, 4, 1, 0), (2, 1, 1, 1), (1, -2, 1, 2))#?

##### 1 Answer

#### Explanation:

Matrices could be multiplied only if first one has as many columns as the second one has rows. In that case it's true - first has 3 columns and second has 3 rows, so we can multiply.

The result will have as many rows as first matrix and as many columns as second matrix.

Everything will be clear from following instruction:

- Lift the second matrix to make room for result.
- To obtain any element take a row directly to the left of it and a column directly above it (for the first element it is
#((1, -3, 2))# and#((1), (2), (1))# ) - multiply them pairwise and take sum:
#1*1+(-3)*2+2*1=1-6+2=-3# - the number you get is this element of resulting matrix

Here is the whole thing:

For other multiplying examples:

How do I do multiplication of matrices?

use wolfram alpha

just google it

use excel (if possible)