Problem 50 - Algebra 1: Concepts and Skills

Question

Use the distributive property to rewrite the expression without parentheses. $$ (3 d-8)(-5) $$

Step-by-Step Solution

Answer

The simplified expression without parenthesis is -15d + 40.

Step 1: Identify the Expression

The expression to be simplified using the distributive property is \( (3d - 8) * -5 \)

Step 2: Apply the Distributive Property

Distribute -5 to each term inside the parenthesis. That is, -5 is multiplied by each term individually. The multiplication operation is performed as follows: -5 * 3d and -5 * -8.

Step 3: Perform the Multiplication

Multiply -5 by 3d to get -15d, and -5 by -8 to get 40.

Step 4: Write the Final Expression

The simplified expression without parenthesis will be -15d + 40.

Key Concepts

Simplifying Algebraic Expressions

When we talk about simplifying algebraic expressions, we are referring to the process of making them easier to understand and work with. This can involve a range of strategies including combining like terms, using the distributive property, and factoring. An important goal when simplifying is to reduce the expression to its most condensed form. This makes it easier to evaluate or use in further calculations. Simplifying is not just about making expressions shorter; it is about clarity and efficiency as well.

Example of Simplification

Consider the expression \( 3d - 8 \). When multiplied by \( -5 \) using the distributive property, we want to combine and simplify the terms as much as possible. By distributing \( -5 \) and then combining, the expression becomes \( -15d + 40 \) which is our simplified result.

Applying Distributive Property

The distributive property is a cornerstone in algebra that allows us to multiply a single term across a sum or difference within parentheses. The formal definition is that \( a(b + c) = ab + ac \), and it works the same way with subtractions: \( a(b - c) = ab - ac \).
The beauty of distributive property lies in its versatility. It simplifies expressions and it's a vital step in many algebraic procedures, including solving equations and multiplying polynomials.

How to Use the Distributive Property

To apply the distributive property, follow these steps: First, look at the term outside of the parentheses, and then multiply it by each term inside the parentheses individually. For our original exercise, the term outside the parenthesis \( -5 \) is multiplied by each term inside the parentheses \( 3d \) and \( -8 \) to get \( -15d \) and \( +40 \) respectively.

Multiplying Polynomials

Multiplying polynomials can seem intimidating at first, but when broken down, it's simply an extension of the distributive property applied multiple times. A polynomial is an expression consisting of variables and coefficients, involving terms in the form of \( ax^n \), where \( a \) is a coefficient, \( x \) is a variable, and \( n \) is the exponent.
When multiplying polynomials, each term of one polynomial must be multiplied by each term of the other polynomial. This process can be likened to a systematic approach of distributing each part of one expression through another.

Visualizing Polynomial Multiplication

A helpful tip is to visualize polynomial multiplication like an area model or a table where you multiply each term of one polynomial across the terms of another, similar to an array. This visual aid helps ensure that all terms are accounted for and properly combined in the final expression.