## Expanding and Simplifying the Expression: (a-3b)^2 + 2a - 6b

This expression involves both squaring a binomial and combining like terms. Let's break it down step by step.

### Step 1: Expanding the Squared Binomial

The term **(a-3b)^2** represents the product of (a-3b) multiplied by itself. We can use the **FOIL** method (First, Outer, Inner, Last) to expand this:

**(a-3b)^2 = (a-3b)(a-3b) = a^2 - 3ab - 3ab + 9b^2 = a^2 - 6ab + 9b^2**

### Step 2: Combining Like Terms

Now our expression looks like this:
**a^2 - 6ab + 9b^2 + 2a - 6b**

We can group the like terms together:

**a^2 + 2a - 6ab - 6b + 9b^2**

### Step 3: Simplified Expression

The final simplified expression is:
**a^2 + 2a - 6ab - 6b + 9b^2**

**This is the expanded and simplified form of the original expression (a-3b)^2 + 2a - 6b.**

**Note:** This expression cannot be further simplified as there are no more like terms.