, −4 2.
A, −4, 4 0 ( ), OA 4 .
4 ( OA) −4.
: |−4| = 4
: .
B, +2, , OB .
2 +2 : |+2| = 2 |2| = 2.
a A , A ( OA) a.
|a| = OA
, .
( ) , , .
,
.
1. . |a| = a, a > 0;
2. . |−a| = a, a < 0;
3. . |0| = 0, a = 0;
4. .
|−a| = |a|;
:
|−4,8| = 4,8
|0| = 0
|−3/8| = |3/8|
, , , .
;
.
.
.
, , . , .
, .
, . , ( ) .
, .
.
−6 −12.
, −6 , ,
|
|
−12.
|−6| < |−12|, , −6 > −12.
18