tunjukkan bahwa | m.n | = | m | | n |

Misalnya m = 2 n = 3
|2 x 3| = |2||3|
|6| = 2.3
6 = 6

misalnya m= -2 n= 7
|-2 x 7| = |-2||7|
|-14| = 2.7
14 = 14

semoga dapat membantu... ^^