Cool Math
Coolmath: Systems of Equations Freaky Things That Can Happen With 2x2's
Reference material and practice problems solving systems of equations using elimination or substitution.
Cool Math
Coolmath: Systems of Equations Solving by Graphing
Reference material and practice problems solving a system of equations by graphing.
Math Planet
Math Planet: Solve Systems of Equations by Graphing
Gain an understanding of how to solve systems of equations by graphing by viewing an example and a video lesson. [2:49]
Cool Math
Coolmath: Systems of Equations Solving by Elimination
Reference material and practice problems solving systems of equations using elimination.
Cool Math
Coolmath: Systems of Equations Solving by Elimination With 3x3's
Reference material and practice problems solving systems of equations using elimination.
Varsity Tutors 
Varsity Tutors: Hotmath: Practice Problems: Systems of Inequalities
Hotmath provides 21 practice problems dealing with systems of equations and inequalities. Each of the practice problems include a step-by-step guide for solving their algebraic problem.
Purple Math
Purplemath: Systems of Non Linear Equations: Definitions
This Purplemath lesson provides formulas, equations, graphs and explanations of systems of equations.
Math Medics
S.o.s. Math: Algebra
This lesson provides basic instruction on the major concepts in algebra. Content includes a focus on fractions, units of conversion, complex numbers, quadratic equations, factorization and roots of polynomials, solving equations, systems...
CK-12 Foundation
Ck 12: Algebra: Systems of Linear Inequalities
[Free Registration/Login may be required to access all resource tools.] Graph and solve systems of linear inequalities.
Texas A&M University
Wtamu Virtual Math Lab: College Algebra: Systems of Linear Equations
This tutorial will show you a four-step process for solving problems involving systems of linear equations. View several examples of Polya's process of problem solving and hone your own skills with practice exercises.
CK-12 Foundation
Ck 12: Algebra: Graphs of Linear Systems
[Free Registration/Login may be required to access all resource tools.] Students find ordered pairs that satisfy a system of linear equations and solve linear systems by graphing. Students examine guided notes, review guided practice,...
Khan Academy
Khan Academy: Linear Systems of Equations Capstone
Solve systems of equations with any number of solutions using any solution method. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Other
Algebra.com: Linear Equation and System Solvers
Linear equations can be solved and graphed using this interactive site. This site allows the user to enter any linear equation in standard form and the y-intercept will be found through a step-by-step process. Systems of inequalities can...
Khan Academy
Khan Academy: Lsn 13: Systems of Equations, Algebraic and Graphical Representations
Lesson 3 of 4 for Passport to Advanced Math. Students will solve systems of equations in two variables in which one equation is linear and the other equation is quadratic or another nonlinear equation; relate properties of the function f...
Lawrence Hall of Science
The Math Page: Skill in Algebra: Simultaneous Linear Equations
Here is a site that clearly and thoroughly explains how to solve systems of linear equations using the methods of combination, substitution, and Cramer's Rule. There are example problems solved, problems for the student to attempt, and...
J Coffman
Joseph Coffman's Lecture Notes: Solving Systems of Equations Algebraically
The lesson explores solving systems of equations algebraically. Topics discussed are the elimination method, substitution method, addition property, and special cases. Examples with detailed solutions and an assessment are included.
Khan Academy
Khan Academy: Systems of Equations With Substitution
Solve systems of equations where one of the equations is solved for one of the variables. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Texas Instruments
Texas Instruments: Solving Systems With Quadratic Equations: Systems of Conics
In this activity, students will plot the graphs of systems of equations and determine the number of real solutions of the system. Then find the solution of the system algebraically.
Khan Academy
Khan Academy: Practice: Solve Systems of Equations With Substitution
In this practice quiz, students are given a system of two equations and asked to substitute the information from one equation into the other in order to determine x and y. Includes hints.
Cool Math
Coolmath: Systems of Equations Introduction to 3x3's
Reference material and practice problems solving systems of 3 equations.
Texas Instruments
Texas Instruments: Writing and Solving Systems of Equations Using Cabri Jr.
Through this introduction to the use of the Cabri Jr. application in the Algebra classroom, students will algebraically and graphically determine equations of lines, as well as determine solutions to systems of linear equations. Using...
Khan Academy
Khan Academy: Systems of Linear Equations Word Problems
In this exercise, students practice solving systems of linear equations in word problems. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
CK-12 Foundation
Ck 12: Algebra: Systems Using Substitution
[Free Registration/Login may be required to access all resource tools.] Solve systems of equations using substitution.
CK-12 Foundation
Ck 12: Algebra: Systems of Linear Equations in Three Variables
[Free Registration/Login may be required to access all resource tools.] This lesson covers solving a system of equations in three variables (x, y, and z).