4.B: Solving Systems by Substitution

Overview

The purpose of this lesson is to learn how to solve two equations using a process called substitution to reduce the two equations down to one.

This lesson will address the following CCRS Standard(s) for Algebra:

  • A.REI.6: Solve systems of linear equations exactly and approximately (e.g. with graphs), focusing on pairs on linear equations in two variables

Directions

  1. Take notes while watching videos below
  2. Go to http://wamap.org and log into our course to complete assignment 4.B with 80% or better.

Watch

Solving Systems by Substitution [9:19] Links to an external site.

Do

Complete assignment 4.B with 80% or better at http://wamap.org Links to an external site.

Summary

In this lesson we have learned:

  • Substitution can be used to solve two equations with the following process:
    • Identify the lone variable
    • Solve for the lone variable
    • Replace this expression in the other equation
    • Solve new equation
    • Use this answer to find the other variable