Processing math: 100%

Recall that the absolute value of a number represents the distance of that number from the origin.

Let's take a look at the number line below.

Since -3 and 3 are at the same distance from the origin, we have

|-3| = |3| = 3.

In general, for any real number a,

|-a| = |a|.

We can use this fact to simplify expressions containing absolute value. Let's see an example.

FLAG

Simplify the expression |-2x|.

EXPLANATION

Since |-a| = |a|, we can rewrite our expression as follows:

|2x|=|2x|

FLAG

|4x|=

a
4
b
|4x|
c
|4x|
d
4
e
16x

|4z7|=

a
|4z7|
b
|47|
c
47
d
47
e
|4z7|

The absolute value operation is distributive with respect to multiplication. This means that the absolute value of a product equals the product of the absolute values.

To demonstrate, consider the following expression:

|(-6) \cdot 2|

We can evaluate this expression in two separate ways:

  • The first is to find the absolute value of the product. In doing this, we get

|(6)2|=|12|=12.

  • The second is to find the product of the absolute values. In doing this, we get

|(6)2|=|6||2|=62=12.

In general

|a \cdot b| = |a|\cdot |b|.

The absolute value operation is also distributive with respect to division. In general,

\left|\dfrac{a}{b}\right| = \dfrac{|a|}{|b|}.

FLAG

Simplify the expression |-18a|.

EXPLANATION

Firstly, since |-a| = |a|, we can write our expression as

|18a|

Then, we distribute the absolute value over the multiplication, and simplify:

|18a|=|18a|=|18||a|=18|a|=18|a|

FLAG

|5x|=

a
|5x|
b
5|x|
c
5
d
5
e
5|x|

Simplify the expression |11x|.

a
|11x|
b
11|x|
c
11|x|
d
11
e
11

Simplify the expression \left|-\dfrac{9}{5c}\right|.

EXPLANATION

Firstly, since |-a| = |a|, we can write our expression as

\left|\dfrac{9}{5c}\right|.

Then, we distribute the absolute value over the division, and simplify:

|95c|=|9||5c|=9|5c|=9|5||c|=95|c|

FLAG

|32x|=

a
32
b
32|x|
c
6x
d
32|x|
e
6x

Simplify the expression |5x3y|.

a
5|x|3|y|
b
5|x|3|y|
c
53
d
15xy
e
15xy
Flag Content
Did you notice an error, or do you simply believe that something could be improved? Please explain below.
SUBMIT
CANCEL