# How to write a system of linear equations in 2 variables

In a system of linear equations, each equation corresponds with a straight line corresponds and one seeks out the point where the two lines intersect. Due to the nature of the mathematics on this site it is best views in landscape mode. If your device is not in landscape mode many of the equations will run off the side of your device should be able to scroll to see them and some of the menu items will be cut off due to the narrow screen width.

Linear Systems with Two Variables A linear system of two equations with two variables is any system that can be written in the form. Also, the system is called linear if the variables are only to the first power, are only in the numerator and there are no products of variables in any of the equations.

Here is an example of a system with numbers. This is easy enough to check. Do not worry about how we got these values. This will be the very first system that we solve when we get into examples. Note that it is important that the pair of numbers satisfy both equations.

Now, just what does a solution to a system of two equations represent? Well if you think about it both of the equations in the system are lines. As you can see the solution to the system is the coordinates of the point where the two lines intersect.

So, when solving linear systems with two variables we are really asking where the two lines will intersect. We will be looking at two methods for solving systems in this section.

The first method is called the method of substitution. In this method we will solve one of the equations for one of the variables and substitute this into the other equation.

This will yield one equation with one variable that we can solve. Once this is solved we substitute this value back into one of the equations to find the value of the remaining variable.

In words this method is not always very clear. Example 1 Solve each of the following systems. We already know the solution, but this will give us a chance to verify the values that we wrote down for the solution. Now, the method says that we need to solve one of the equations for one of the variables.

This means we should try to avoid fractions if at all possible. This is one of the more common mistakes students make in solving systems. Here is that work.

As with single equations we could always go back and check this solution by plugging it into both equations and making sure that it does satisfy both equations.

Note as well that we really would need to plug into both equations.Learn about linear equations that contain two variables, and how these can be represented by graphical lines and tables of values.

Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. A "system" of equations is a set or collection of equations that you deal with all together at once.

Linear equations (ones that graph as straight lines) are simpler than non-linear equations, and the simplest linear system is one with two equations and two variables.

In mathematics, a system of linear equations (or linear system) For three variables, each linear equation determines a plane in three-dimensional space, and the solution set is the intersection of these planes.

Thus the solution set may be a plane, a line, a single point, or the empty set. Writing Linear Equations in Two Variables The point-slope form can be used to find an equation of the line passing through two points (x 1, y 1) and (x 2, y 2).

To do this, first find the slope of the line and then use the point-slope form to obtain the equation.

## How to Solve a System of Two Linear Equations: 7 Steps

Linear equations considered together in this fashion are said to form a system of equations. As in the above example, the solution of a system of linear equations can be a single ordered pair.

The components of this ordered pair satisfy each of the two equations. 90 Chapter 2 Graphing Linear Equations and Linear Systems Lesson Solving Equations Using Graphs Step 1: To solve the equation ax + b = cx + d, write two linear equations.

ax + b = cx + d Step 2: Graph the system of linear equations. The x-value of the solution of the system of linear equations is the solution of the equation ax + b = cx + d.

EXAMPLE 1 Solving an Equation Using a Graph.

System of Linear Equations and Matrix Inversion