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Algebra Core Concepts

Sep 15, 2025

Overview

This review covers core algebra topics from intervals and equations to functions, graphing, exponents, scientific notation, and systems of equations.

Intervals and Absolute Value

  • Intervals can be written in set-builder notation and graphed on a number line.
  • Absolute value means the distance of a number from zero; |a| is always non-negative.

Tables, Graphs, and Functions

  • Complete tables of values and graph equations like y = x² + 1, y = 3x + 1, and y = 2|x + 4|.
  • The domain of a function is the set of all possible x-values; the range is the set of all possible y-values.
  • Relations are functions if each x-value corresponds to exactly one y-value.

Solving Linear Equations and Word Problems

  • Solve linear equations by isolating the variable on one side.
  • Translate word problems into equations (e.g., perimeter, discount, allowances) and solve for unknowns.
  • Set up and solve average and age-related problems algebraically.

Algebraic Formulas and Manipulations

  • Solve formulas for a specified variable (e.g., solve A = P + Prt for t).
  • Simplify expressions; eliminate negative exponents and use exponent rules.
  • Convert numbers between scientific and decimal notations.

Graphs and Equation Forms

  • Write equations in slope-intercept form (y = mx + b) for graphing.
  • Find the equation of a line given two points or a point and a condition (parallel or perpendicular).
  • Graph quadratic functions and compare transformations.

Systems of Equations

  • Solve linear systems using substitution or elimination.
  • Set up systems from word problems involving tickets, mixtures, ages, coins, and rates.
  • Solutions give the values satisfying all equations in the system.

Key Terms & Definitions

  • Interval notation — Describes a set of numbers between two endpoints.
  • Absolute value — The non-negative value of a number (distance from zero).
  • Domain — All possible input (x) values for a function.
  • Range — All possible output (y) values for a function.
  • Slope-intercept form — Line equation y = mx + b, where m is slope, b is y-intercept.
  • System of equations — A set of equations to be solved together.
  • Scientific notation — Writing numbers as a × 10ⁿ for large/small values.

Action Items / Next Steps

  • Practice solving all sample equations and word problems.
  • Complete tables and graph all given equations as requested.
  • Review definition and identification of functions, domain, and range.
  • Convert numbers between scientific and decimal notations.
  • Prepare to explain and apply exponent rules.