To expand the expression $(x + 3)^3$, we can use the binomial theorem or apply the cube formula directly.

The expansion of $(a + b)^3$ is given by:

$(a + b)^3 = a^3 + 3a^2b + 3ab^2 + b^3$

For $(x + 3)^3$, let $a = x$ and $b = 3$. Applying the formula:

$(x + 3)^3 = x^3 + 3(x^2)(3) + 3(x)(3^2) + 3^3$

Simplifying each term:

$(x + 3)^3 = x^3 + 9x^2 + 27x + 27$

So, the expanded form of $(x + 3)^3$ is:

$x^3 + 9x^2 + 27x + 27$

Would you like further details or have any questions?

Here are 5 related questions to consider:

1. How would you expand $(x - 3)^3$?
2. What is the general formula for $(x + y)^n$ using the binomial theorem?
3. Can you factor the expanded form of $(x + 3)^3$?
4. How would the expansion change if the exponent was 4, i.e., $(x + 3)^4$?
5. How can you use this expansion to solve cubic equations?

Tip: When expanding binomials, pay attention to the powers of each term and the binomial coefficients.