The expression you provided is:

$\frac{4(1 - 3^n)}{1 - 3}$

Let's simplify this step by step:

1. Simplify the denominator $1 - 3$: $1 - 3 = -2$

2. Now substitute the result into the expression: $\frac{4(1 - 3^n)}{-2}$

3. Simplify the fraction: $\frac{4(1 - 3^n)}{-2} = -2(1 - 3^n)$

4. Finally, distribute the $-2$: $-2(1 - 3^n) = -2 + 2 \cdot 3^n$

So, the simplified expression is: $2 \cdot 3^n - 2$

Would you like further details or have any questions?

Here are some related questions for practice:

1. Simplify: $\frac{5(1 - 2^n)}{1 - 2}$
2. Simplify: $\frac{6(1 - 4^n)}{1 - 4}$
3. Solve for $n$: $2 \cdot 3^n - 2 = 16$
4. Expand: $3 \cdot (2 - 5^n)$
5. Factor: $2 \cdot 3^n - 2$

Tip: When simplifying expressions with common denominators, always simplify the denominator first to avoid unnecessary complexity.