SOLUTION: Find BA when A = 5 -3 and B= 2 2 -3 2 -2 6 I tried 2*5+2*-3 2*-3+2*2 -2*5+6*-3 -2*-3+6*2 and got 4 2

Algebra ->  Matrices-and-determiminant -> SOLUTION: Find BA when A = 5 -3 and B= 2 2 -3 2 -2 6 I tried 2*5+2*-3 2*-3+2*2 -2*5+6*-3 -2*-3+6*2 and got 4 2       Log On


   

Question 1175792: Find BA when A = 5 -3 and B= 2 2
-3 2 -2 6
I tried 2*5+2*-3 2*-3+2*2
-2*5+6*-3 -2*-3+6*2 and got 4 2
-8 18
Found 2 solutions by ikleyn, Alan3354:
Answer by ikleyn(52788) About Me  (Show Source):
You can put this solution on YOUR website!
.

    B * A = %28matrix%282%2C2%2C+2%2C2%2C+-2%2C6%29%29 . %28matrix%282%2C2%2C+5%2C-3%2C+-3%2C2%29%29 =  = %28matrix%282%2C2%2C+4%2C+-2%2C++-28%2C+18%29%29.

Solved.


To see the formula for  2x2-matrices,  look into this  Wikipedia article

https://en.wikipedia.org/wiki/Matrix_multiplication_algorithm



Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Find BA when A = 5 -3 and B= 2 2
-3 2 -2 6
I tried 2*5+2*-3 2*-3+2*2
-2*5+6*-3 -2*-3+6*2 and got 4 2
-8 18
===============================
Find BA when A = 5 -3 and B= 2 2
-3 2 -2 6
-----
| 2  2|   | 5 -3|   |a  b|
|-2  6| * |-3  2| = |c  d|
---

a = 2*5+2*-3 = 4
b = 2*-3+2*2 = -2
c = -2*5+6*-3 = -28
d = -2*-3+6*2 = 18
---
|  4  -2|
|-28  18|