What are the rules of absolute

The absolute value (or modulus) | x | of a real number x is the non-negative value of x without regard to its sign. For example, the absolute value of 5 is 5, and the absolute value of −5 is also 5. The absolute value of a number may be thought of as its distance from zero along real number line.

Step-by-step explanation:

An absolute value equation in the form |ax+b|=c | a x + b | = c has the following properties: If c<0,|ax+b|=c has no solution. If c=0,|ax+b|=c has one solution. If c>0,|ax+b|=c has two solutions.

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Step-by-step explanation:  Algebra rules for absolute values are listed below. 
Piecewise Definition:|a|={aifa≥0−aifa<0|a|={aifa≥0−aifa<0

Square root definition:|a|=√a2|a|=a2

Rules:

1. |–a| = |a|2.  |a| ≥ 0 3.  

Products: |ab| = |a||b| 4.  

Quotients: |a / b| = |a| / |b| 5.  

Powers: |an| = |a|n6.  

Triangle Inequality:         |a + b| ≤ |a| + |b| 7.  

Alternate Triangle Inequality:         |a – b| ≥ |a| – |b| 

PLEASE BE CAREFUL!!    Sums:   |a + b| is not the same as |a| + |b|                                                  Differences:   |a – b| is not the same as |a| – |b|  

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk