How to solve a System of Equations using Substitution Method

Algebrator can easily solve problems such as the one you posted on Yahoo Answers.

You start by entering it in an intuitive math editor. You may enter each equation on a line of its own and the software

will solve this "system of two equations in two unknowns".

An example using your system of equations is described below.

To control the method by which the system is solved, use the drop-down menu "Solution->Settings", where elimination, substitution and Cramer rule are shown as options.

For example to solve a system of equations using the Substitution method, enter the equations into the software and select Substitution as the solution method.

By clicking on the "Explain" button, Algebrator will explain the each step.

In this case, we need to expand this term by multiplying a term and an expression.

Algebrator now groups all variable terms on one side, and all constant terms on the other side.

Algebrator now groups all variable terms on one side, and all constant terms on the other side.

t is important to note that the "visibility" button allows us to see more or less steps involved in the process.

In order to eliminate X in the first equation we need to substitute the right side of the second equation for X in the first equation.

The given system of equations is consistent and independent. By clicking on the "Graph" button, the graph will be displayed.

It is important to understand that anytime you are solving a system of equations you are answering the basic question "Do the graphs of these equation touch?". They may touch in one point (one solution), no points (no solutions) or an infinite number of points (i.e. the equations define the same line). For this reason, it is always helpful to press "Graph All" after the solution as this allows you to see a graph of the equations and better understand the solution you obtained.