Algebra Essentials: Background You’ll Need 3

  • Learn to spot the difference between letters and numbers in math expressions and combine similar terms to simplify them.

Simplifying Algebraic Expressions

Algebraic expressions are combinations of variables, constants, and mathematical operations. Simplifying these expressions is a fundamental skill in algebra that helps us solve equations more easily and understand mathematical relationships better.

Before we begin simplifying, it’s crucial to understand the difference between variables and constants.

Constant and Variables

In the study of mathematics and programming, two fundamental concepts that frequently arise are constants and variables. Constants are elements that remain unchanged within a given scenario, providing a stable and known value that can simplify calculations and coding. On the other hand, variables represent elements whose values can change, depending on the conditions of the problem or the inputs to a program. These concepts are crucial for developing equations, functions, and algorithms that accurately model real-world phenomena. Understanding the differences between constants and variables is key to mastering mathematical expressions and enhancing problem-solving skills.

Aspect Constant Variable
Value Stability Remain fixed and unchanging. Can change based on context or conditions.
Representation Fixed numerical values (e.g., [latex]5, -3, \frac{1}{2}[/latex]) Letters or symbols that represent unknown or changing values (e.g., [latex]x, y, z[/latex])
Role Known values in calculations and programming. Unknown or variable quantities to be determined.
Identify the constant and variables of the following algebraic expressions.

  • [latex]3x+4[/latex]

  • [latex]x^2 +3x+4[/latex]

  • [latex]2xy[/latex]

Combining Like Terms

Combining like terms is an essential technique in simplifying algebraic expressions. To combine like terms, first identify terms within the expression that have identical variables raised to the same power. Once identified, you can add or subtract their coefficients while keeping the variable part unchanged.

Characteristics of Like Terms:

  • Same Variables: Like terms must involve the exact same variables. For example, [latex]2x[/latex] and [latex]5x[/latex] are like terms because both contain the variable [latex]x[/latex].
  • Same Exponents: The variables in like terms must be raised to the same power. For instance, [latex]3x^2[/latex] and [latex]-7x^2[/latex] are like terms because both terms include [latex]x[/latex] squared.
  • Coefficients Can Vary: The coefficients (numerical values multiplying the variables) can be different. In the examples above, [latex]2[/latex] and [latex]5[/latex] are different coefficients for terms involving [latex]x[/latex], and [latex]3[/latex] and [latex]-7[/latex] are different coefficients for terms involving [latex]x^2[/latex].

How to: Simplify Algebraic Expressions by Combining Like Terms

  1. Identify variables and constants in the expression.
  2. Group like terms together.
  3. Combine like terms by adding or subtracting their coefficients.
  4. Write the simplified expression with unlike terms separated.
Simplify the following algebraic expression:

[latex]5x-2y-8x+7y[/latex]

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