Basics

A line is a flat straight figure extending infinitely through two points. (See Line L above.)

x-axis = horizontal

x = horizontal coordinate

(x, y) = point representing horizontal and vertical coordinates on Line L

Slope refers to the steepness of a line.

m = slope

**Formulas** (**Mathematics Formula Sheet**)

slope of a line

m =

slope-intercept form of the equation of a line

y = mx + b

point-slope form of the equation of a line

y – y_{1} = m(x – x_{1})

**Formulas (NOT on Mathematics Formula Sheet)**

slope as change

m =

slope-intercept b

b = y – mx

standard form of the equation of a line

ax + by + c = 0