 # Algebra 1 - 4th Edition

## Chapter 4: Linear Equations

Some links are repeated for use with more than one lesson.

### This site applies to the entire chapter.

http://www.freemathhelp.com/systems-linear-equations.html
This site contains an overview of systems of linear equations along with step-by-step examples.

### 4.1 Coordinates and Graphs

http://www.purplemath.com/modules/plane.htm
This series of pages introduces the plotting of ordered pairs on the four quadrants of the Cartesian coordinate system.

### 4.2 Slope and Rate of Change

http://www.algebra.com/algebra/homework/Linear-equations/movie-linear-equations.lesson
A Flash video tutorial about lines and linear equations.

http://www.coolmath.com/algebra/Algebra1/06Lines/05_whatstheslope.htm
This page has a detailed definition on the slope of a line.

This site contains an explanation of the slope of a line and how to calculate it.

http://www.algebra.com/algebra/homework/Linear-equations/slope.solver
Online solver to calculate slope given two points.

### 4.3 Graphing Linear Equations

http://www.explorelearning.com/index.cfm?method=cResource.dspResourcesForCourse&CourseID=242
This site has gizmos that show different parts to graphing linear equations.

http://www.math.com/school/subject2/lessons/S2U4L3GL.html
This site has the steps on how to graph linear equations with graphs to demonstrate.

### 4.4 Writing Linear Equations

http://www.algebralab.org/practice/practice.aspx?file=Algebra_Gulliksen1cntd.xml
This page contains practice problems on writing linear equations when looking at a graph and when looking at a pair of points.

http://www.algebralab.org/practice/practice.aspx?file=Algebra_Gulliksen2.xml
This page gives practice writing and interpreting a linear equation based on a real life situation.

### 4.5 Intercepts, Zeros and Roots of Linear Equations

http://www.mathsisfun.com/algebra/finding-intercepts-equation.html
This site discusses and provides practice for finding the intercepts of a linear equation.

http://www.mathsisfun.com/algebra/line-equation-2points.html
This site discusses and provides practice for finding the equation of a line from two points.

### 4.6 Slopes of Parallel and Perpendicular Lines

http://www.algebralab.org/lessons/lesson.aspx?file=Geometry_CoordParallelPerpendicular.xml
This site explains the slopes of parallel and perpendicular lines with practice problems.

http://www.purplemath.com/modules/slope2.htm
This page defines the slopes of parallel and perpendicular lines and contains examples.

### 4.7 Using a Graphing Calculator

http://www.coolmath.com/graphit/index.html
This page contains an online graphing calculator that can be used to graph linear equations. (Requires Java.)