A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.

To find the average of these 4 numbers add them together then divide by 4:

\( \frac{11 + 5 + 12 + 4}{4} \) = \( \frac{32}{4} \) = 8

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

5 + (4 + 4) ÷ 2 x 2 - 4²
P: 5 + (8) ÷ 2 x 2 - 4²
E: 5 + 8 ÷ 2 x 2 - 16
MD: 5 + \( \frac{8}{2} \) x 2 - 16
MD: 5 + \( \frac{16}{2} \) - 16
AS: \( \frac{10}{2} \) + \( \frac{16}{2} \) - 16
AS: \( \frac{26}{2} \) - 16
AS: \( \frac{26 - 32}{2} \)
\( \frac{-6}{2} \)
-3

The equation for this sequence is:

a_n = a_n-1 + 1

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 + 1
a₆ = 5 + 1
a₆ = 6

To add or subtract terms with exponents, both the base and the exponent must be the same. In this case they are so add the coefficients and retain the base and exponent:

7b³ + 6b³
(7 + 6)b³
13b³