Question

Given `A=((-1, 2), (3, 4))` and `B=((-4, 3), (5, -2))`, how do you find BA?

Answer 1

`BA = ((13,4), (-11,2))`

Explanation:

To multiply matrices:

1. . Are they compatible?
   These are both 2 X 2, Yes, The answer will also be 2 X 2.

2. Correct order. AB is not the same as BA

3. Multiply each value in a row in turn BY the values in a column and add the answers.

`B=((-4, 3), (5, -2))` and `A=((-1, 2), (3, 4))`

The calculations are :

top row x first column: `-4*-1+3*3 = 4+9 =13`
top row x second column:`-4*2+3*4 =-8+12 =4`
bottom row x first column:`5*-1*+ -2*3=-5-6 =-11`
bottom row x second column:`5*2+2*4 =10-8 =2`

`BA = ((13,4), (-11,2))`