We can start doing more complicated things now.

Here's another matrix called B:

B = [ row 1: 7 , 1  row 2: -4 , 0 ]

Let's find

3B - A

Just write it out with the matrices and start working:

3B - A = 3 [ row 1: 7 , 1  row 2: -4 , 0 ] - [ row 1: -4 , 0  row 2: 3 , 6 ]

 

= [ row 1: 21 , 3  row 2: -12 , 0 ] - [ row 1: -4 , 0  row 2: 3 , 6 ] = [ row 1: 25 , 3  row 2: -15 , -6 ]

 


YOUR TURN:

Here are some matrices:

A = [ row 1: -8 , 9  row 2: 1 , -3 ]             B = [ row 1: 2 , -6  row 2: - 5, 10 ]
 

C = [ row 1: 0 , -4  row 2: 3 , 7 ]


Find 2C.

Find A + B.

Find A + 2C.

Find 5A - B - 3C.