IfB=[�]thenBT=⎡⎢⎣�⎤⎥⎦Now considerAT−BTthat isAT−BT=⎡⎢⎣34�⎤⎥⎦−⎡⎢⎣�⎤⎥⎦=⎡⎢⎣3−()420⎤⎥⎦=⎡⎢⎣43⎤⎥⎦HenceAT−BT=⎡⎢⎣43⎤⎥⎦.