Answer :

To express [tex]\( \sqrt{45} \)[/tex] in its simplest radical form, we need to follow a series of steps involving factorization and simplification of the square root.

### Step-by-Step Solution:

1. Factorize the Number Inside the Square Root:

First, we need to find the factors of 45. Notice that:
[tex]\[ 45 = 9 \times 5 \][/tex]

Therefore, we can write:
[tex]\[ \sqrt{45} = \sqrt{9 \times 5} \][/tex]

2. Use the Property of Square Roots:

We use the property of square roots that the square root of a product is the product of the square roots:
[tex]\[ \sqrt{45} = \sqrt{9 \times 5} = \sqrt{9} \times \sqrt{5} \][/tex]

3. Simplify the Square Roots:

We know that [tex]\( \sqrt{9} \)[/tex] is a perfect square, specifically:
[tex]\[ \sqrt{9} = 3 \][/tex]

Therefore, we can simplify:
[tex]\[ \sqrt{45} = 3 \times \sqrt{5} \][/tex]

So, the simplest radical form of [tex]\( \sqrt{45} \)[/tex] is:

[tex]\[ \boxed{3 \sqrt{5}} \][/tex]