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Home » System of Equations » Substitution Method

# Using the Substitution Method to

Solve Systems of Equations

## Steps for Using the Substitution Method in order to Solve Systems of Equations

## Example 1

## Example 2

## Example 3

## Example 4

### Take a look at the questions that other students have submitted:

## Other Lessons You Might Like on Systems of Equations

# Like This Page?

Solve Systems of Equations

The substitution method is one of two ways to solve systems of equations without graphing.

You might ask yourself, "Why wouldn't I just want to graph the equations to find the solution?" Well there are many reasons...

You may not have graph paper or an accurate way to graph the equations, thus making it hard to identify the solution.

Or, as the equations become more difficult, the solution is not always an identifiable point on the graph. This means that the solution may contain decimals or fractions, which is not easy to identify on a graph.

Once you learn the algebraic method for solving a system of equations, you will probably find that it becomes your preferred method. Graphing becomes too tedious.

The good news is that there are two methods, which makes this process easier depending on the problems you are given.

So, let's get to it!

The following steps can be used as a guide as you read through the examples for using the substitution method.

- Solve 1 equation for 1 variable. (Put in y = or x = form)
- Substitute this expression into the other equation and solve for the missing variable.
- Substitute your answer into the first equation and solve.
- Check the solution.

These directions will make a lot more sense when you study the examples below.

The next example demonstrates a situation where it is easier to solve for x initially.

Let's take a look at another example. You'll find this very interesting! Pay close attention to the very last step of the solution.

Ok... one more unique example. Again, pay attention to the end result.

Using substitution when equations are in standard form.

Solving the system: x - y = 5 & x= -4y

How do I know which variable to start with?

To ask a question, please visit my Math Forum.

Systems of Equations Unit

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