Problem 4 - College Algebra Essentials

Question

$$\text { Factor out the greatest common factor.}$$ $$4 x^{2}-8 x$$

Step-by-Step Solution

Answer

The greatest common factor is \(4x\), and the factored expression is \(4x(x - 2)\).

Step 1: Identify the GCF of the Terms

Examine the expression \(4x^{2}-8x\) and identify the GCF of the two terms. Both \(4x^{2}\) and \(8x\) can be divided by \(4x\) without leaving a remainder, so the GCF is \(4x\).

Step 2: Divide Each Term by the GCF

Divide each term of the expression by the GCF to get the remaining part of the expression. This gives: \(4x^{2}\) divided by \(4x\) equals \(x\), and \(8x\) divided by \(4x\) equals \(2\). The remaining expression is \(x-2\).

Step 3: Write Out the Factored Expression

The factored expression is the GCF times the remaining expression, which is \((4x)(x - 2)\).

Key Concepts

Greatest Common Factor

The greatest common factor (GCF) is an essential concept in algebra that helps simplify expressions by finding the largest value that divides all terms of the expression evenly. In the expression \(4x^{2} - 8x\), the GCF is found by first identifying the greatest numerical factor and the highest power of any common variables.

• Looking at the numbers 4 and 8, the largest number that divides both is 4.
• For the variable \(x\), the lowest power present in both terms is \(x^1\).

Thus, the GCF for \(4x^{2} - 8x\) is \(4x\). This means that \(4x\) can be factored out of each term, simplifying the expression and making further calculations easier. Knowing how to find the GCF is crucial because it is a foundational step in factoring polynomials.

Polynomials

Polynomials are expressions made up of variables and coefficients, structured with operations of addition, subtraction, and non-negative integer exponents. In the exercise \(4x^{2} - 8x\), we are dealing with a polynomial with two terms: \(4x^{2}\) and \(-8x\).
This polynomial is called a binomial because it consists of two distinct parts or terms. Each term is a combination of a numerical coefficient and a variable raised to an integer power.
Polynomials can have many terms and varying degrees, but working with them involves similar basic operations like addition or subtraction, focusing on combining like terms and simplifying the structure when possible. Understanding the composition of polynomials aids in recognizing opportunities to simplify via factoring, especially when determining common factors.

Algebraic Simplification

Algebraic simplification is the process of reducing an expression into its simplest form, making it easier to handle or solve in algebraic problems. There are various strategies for achieving this, but factoring out the greatest common factor (GCF) is often the first step.
For the given expression \(4x^{2} - 8x\), simplification begins by identifying the GCF as \(4x\).

• We divide each term of the polynomial by this GCF: \(4x^{2} \div 4x = x\) and \(8x \div 4x = 2\).
• These quotients form a new simpler expression \(x - 2\), which when multiplied back by the GCF \(4x\) gives us the original expression.

This method not only simplifies the expression into a more manageable form but also facilitates solving equations involving the polynomial by clearly revealing its factors. Mastering algebraic simplification enhances numerical problem-solving skills and streamlines complex equations.