|5A-2B|
= |5a-2d, 3b, 3c|
= 3*3*|5a-2d, b, c|
= 9( |5a, b, c| + |-2d, b, c| )
= 9( 5|a, b, c| - 2 |d, b, c| )
= 9 (5|A| - 2|B|)
= 9 (5*3 -2*4)
= 9 * 7
= 63.
|5A-2B|
= |5a-2d, 3b, 3c|
= 3*3*|5a-2d, b, c|
= 9( |5a, b, c| + |-2d, b, c| )
= 9( 5|a, b, c| - 2 |d, b, c| )
= 9 (5|A| - 2|B|)
= 9 (5*3 -2*4)
= 9 * 7
= 63.