The equation for this sequence is:

a_n = a_n-1 + 5

where n is the term's order in the sequence, a_n is the value of the term, and a_n-1 is the value of the term before a_n. This makes the next number:

a₆ = a₅ + 5
a₆ = 21 + 5
a₆ = 26

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).

A number with an exponent (b^e) consists of a base (b) raised to a power (e). The exponent indicates the number of times that the base is multiplied by itself. A base with an exponent of 1 equals the base (b¹ = b) and a base with an exponent of 0 equals 1 ( (b⁰ = 1).

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

2 + (5 + 5) ÷ 4 x 4 - 4²
P: 2 + (10) ÷ 4 x 4 - 4²
E: 2 + 10 ÷ 4 x 4 - 16
MD: 2 + \( \frac{10}{4} \) x 4 - 16
MD: 2 + \( \frac{40}{4} \) - 16
AS: \( \frac{8}{4} \) + \( \frac{40}{4} \) - 16
AS: \( \frac{48}{4} \) - 16
AS: \( \frac{48 - 64}{4} \)
\( \frac{-16}{4} \)
-4

The amount of flour you need is (2 - 1\(\frac{5}{8}\)) cups. Rewrite the quantities so they share a common denominator and subtract:

(\( \frac{16}{8} \) - \( \frac{13}{8} \)) cups
\( \frac{3}{8} \) cups
\(\frac{3}{8}\) cups