Proving a Linear System

annoymage

1. The problem statement, all variables and given/known data

let A (2x2 real matrices),

If AB=BA for all B (2x2 real matrices) , show that A=bI₂ for all b ( b are real numbers)

2. Relevant equations

N/A

3. The attempt at a solution

can anyone give me clue for this one too

Gregg

Having done the other one, you can definitely do this one. Just formulate it in a similar way.

AB-BA=0