I have some geometry homework and I need help.

How do you multiply a regular number by a matrix?

For example: 5[3/-1]

Please explain matrices in general as I have no idea on the subject.

Just multiply each entry in the matrix by the number.....example

3 [ 1 2 ] = [ 3 6 ]

[ 6 10 ] [18 30 ]

Uh. No?

THANKS CPHILL