This week in precalc 11 we learned about the absolute value of a real number.

The absolute value is  the principal square root of a number, it is the distance from a to 0 on the number line. The absolute value is always positive. The sign used to represent it is | |.

For example, let’s say we’re trying to find the absolute value of | -39 | = 39 because the distance between -39 is 39 (the number has to be positive). Another example would be | 24 | = 24  which means that the distance between 24 and 0 is 24.

The absolute value bars do not work like parenthesis or brackets. For example, if you want to simplify – | -25 |.

Because the absolute value of negative 25 is positive 25, we end up with negative positive 25, which at the end gives us negative 25.

– | – 25 | = – ( +25 ) = -25