GMAT Quantitative Review
3.0 Math Review
3.2 Algebra
9. Absolute Value
The absolute value of x, denoted 
, is defined to be x if 
and −x if 
. Note that 
denotes the nonnegative square root of x2, and so 
.
The absolute value of x, denoted , is defined to be x if and −x if . Note that denotes the nonnegative square root of x2, and so .