Problem 43 - College Algebra and Calculus: An Applied Approach

Question

Simplify the expression.\(3^{n} \cdot 3^{2 n}\)

Step-by-Step Solution

Answer

The simplified form of the expression \(3^{n} \cdot 3^{2n}\) is \(3^{3n}\).

Step 1: Write Out Expression

The original expression is \(3^{n} \cdot 3^{2n}\).

Step 2: Apply Properties of Exponents

Because we are multiplying two quantities with the same base (3), we can add the exponents: \(3^{n + 2n}\).

Step 3: Simplify Exponents

Simplify the exponent, \(n + 2n = 3n\), giving us the expression: \(3^{3n}\).

Key Concepts

Properties of Exponents

Understanding the properties of exponents is key to mastering expressions like the one in our exercise. Exponents are a shorthand way to express repeated multiplication of a number by itself. They have certain properties that make manipulation easier.
When multiplying expressions that have the same base, like in our exercise, a crucial property is used:

• Product of Powers Property: For same bases, simply add the exponents. That is, for any base \(a\), \(a^m \cdot a^n = a^{m+n}\).

Applying this principle allows you to consolidate separate terms into one, making calculations simpler. It's important to recognize these properties to handle more complex expressions efficiently. Once the exponents are added, the base remains unchanged, so for \(3^n \cdot 3^{2n}\), adding the exponents gives \(3^{n + 2n} = 3^{3n}\). This transformation simplifies the expression significantly.

Simplifying Expressions

Simplifying expressions isn't just about reducing them to their simplest form. It involves a systematic process using mathematical rules and properties. Let's break it down.
To simplify any expression:

• Identify same-base terms: Check if there are terms that can be combined—like terms containing the same base number.
• Use Properties of Exponents: Apply them where applicable, as in our exercise where we used the product of powers property.
• Combine terms: After using the properties, calculate or rewrite the resulting expression for clarity.

By following these steps, mathematical expressions can become manageable and solve-able. In our exercise, the simplification reduced the terms multiplication of power bases into a single exponent, \(3^{3n}\), which is cleaner and prompts further calculations with ease.

Algebraic Manipulation

Algebraic manipulation involves rearranging and rewriting equations or expressions to reveal the underlying mathematical intentions. This technique allows us to focus on simplifying or resolving the equation more efficiently.
Here are important points for successful algebraic manipulation:

• Recognition: Identify terms that can be manipulated using known properties of algebra, like addition or multiplication rules.
• Reordering: Change the order of terms, keeping properties, such as the commutative property, in mind.
• Simplification: Combine like terms, and perform operations such as addition of exponents or factoring out common bases.

In our example, algebraic manipulation involved the recognition of terms with matching bases and the addition of exponents. This allowed the transformation from the initial expression into a much simpler one. The efficient use of properties and consistent practice helps in solving equations easily and confidently. In cases like simplifying \(3^n \cdot 3^{2n}\), recognizing the steps where algebraic tactics are applied is essential for comprehension and execution.