## Expanding (a + 3)(a + 3)

The expression (a + 3)(a + 3) represents the multiplication of two identical binomials. To find the answer, we can use the **FOIL** method, which stands for:

**F**irst: Multiply the first terms of each binomial.**O**uter: Multiply the outer terms of the binomials.**I**nner: Multiply the inner terms of the binomials.**L**ast: Multiply the last terms of each binomial.

Let's apply this to our expression:

**F:** a * a = **a²**
**O:** a * 3 = **3a**
**I:** 3 * a = **3a**
**L:** 3 * 3 = **9**

Now, we add all the terms together: a² + 3a + 3a + 9

Finally, we combine the like terms:

**a² + 6a + 9**

Therefore, the expanded form of (a + 3)(a + 3) is **a² + 6a + 9**.

**Note:** (a + 3)(a + 3) is also equivalent to **(a + 3)²**. This form highlights that the expression is a **perfect square trinomial**, which is a trinomial resulting from squaring a binomial.