|3-12|

Rewrite 12 as 22⋅3.

Factor 4 out of 12.

|3-4(3)|

Rewrite 4 as 22.

|3-22⋅3|

|3-22⋅3|

Pull terms out from under the radical.

|3-(23)|

Multiply 2 by -1.

|3-23|

|3-23|

3-23 is approximately -0.46410161 which is negative so negate 3-23 and remove the absolute value

-(3-23)

Apply the distributive property.

-1⋅3-(-23)

Multiply -1 by 3.

-3-(-23)

Multiply -2 by -1.

-3+23

The result can be shown in multiple forms.

Exact Form:

-3+23

Decimal Form:

0.46410161…

Divide |3- square root of 12|