Solve problems 4, 6, and 8 and complete numeric patterns b) and e).

Let the missing number be $x$.

Combine the constant terms:

Subtract 30 from both sides:

The missing number is $\boxed{68}$.

Let the missing number be $y$.

First, calculate the sum in the parentheses:

Add 8 to both sides:

The missing number is $\boxed{20}$.

Let the missing number be $z$.

Subtract 16 from both sides:

Multiply both sides by -1:

Multiply both sides by 3:

The missing number is $\boxed{36}$.

The pattern is $20, 18, 16, 14, \dots$
This is an arithmetic sequence where each term is 2 less than the previous term. The common difference is $-2$.
The next three terms are:
$14 - 2 = 12$
$12 - 2 = 10$
$10 - 2 = 8$
The completed pattern is $\boxed{20, 18, 16, 14, 12, 10, 8}$.

The pattern is $3, 9, 27, \dots$
This is a geometric sequence where each term is 3 times the previous term. The common ratio is 3.
The next three terms are:
$27 \times 3 = 81$
$81 \times 3 = 243$
$243 \times 3 = 729$
The completed pattern is $\boxed{3, 9, 27, 81, 243, 729}$.

The pattern is $7, 10, \dots$
This is an arithmetic sequence where each term is 3 more than the previous term. The common difference is 3.
The next three terms are:
$10 + 3 = 13$
$13 + 3 = 16$
$16 + 3 = 19$
The completed pattern is $\boxed{7, 10, 13, 16, 19}$.

The pattern is $16, 14, \dots$
This is an arithmetic sequence where each term is 2 less than the previous term. The common difference is $-2$.
The next three terms are:
$14 - 2 = 12$
$12 - 2 = 10$
$10 - 2 = 8$
The completed pattern is $\boxed{16, 14, 12, 10, 8}$.