The absolute value is the positive magnitude of a particular number or variable and is indicated by two vertical lines: \(\left|-5\right| = 5\). In the case of a variable absolute value (\(\left|a\right| = 5\)) the value of a can be either positive or negative (a = -5 or a = 5).

Use PEMDAS (Parentheses, Exponents, Multipy/Divide, Add/Subtract):

5 + (4 + 5) ÷ 3 x 4 - 2²
P: 5 + (9) ÷ 3 x 4 - 2²
E: 5 + 9 ÷ 3 x 4 - 4
MD: 5 + \( \frac{9}{3} \) x 4 - 4
MD: 5 + \( \frac{36}{3} \) - 4
AS: \( \frac{15}{3} \) + \( \frac{36}{3} \) - 4
AS: \( \frac{51}{3} \) - 4
AS: \( \frac{51 - 12}{3} \)
\( \frac{39}{3} \)
13

The commutative property states that, when adding or multiplying numbers, the order in which they're added or multiplied does not matter. For example, 3 + 4 and 4 + 3 give the same result, as do 3 x 4 and 4 x 3.

A factorial has the form n! and is the product of the integer (n) and all the positive integers below it. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120.

The factors of a number are all positive integers that divide evenly into the number. The factors of 64 are 1, 2, 4, 8, 16, 32, 64.