Algebra 1: Fundamentals

Variable

A symbol (usually a letter) representing an unknown value

Coefficient

The numerical factor multiplied by a variable (e.g., 3 in 3x)

Constant

A fixed value that does not change (e.g., 5 in x + 5)

Expression

A combination of numbers, variables, and operations without an equals sign

Equation

A mathematical statement that two expressions are equal (contains =)

Linear Equation

An equation whose graph is a straight line; standard form: ax + b = 0

Slope

Rise over run (Δy/Δx); measures steepness of a line

Slope-Intercept Form

y = mx + b, where m is slope and b is y-intercept

Y-Intercept

The point where a line crosses the y-axis (x = 0)

System of Equations

Two or more equations with the same variables solved simultaneously