A linear equation is an equation of the first degree, meaning that the highest exponent of any variable is 1. Linear equations can have one variable, two variables, or more. Linear equations can be solved using a variety of methods, including the graphical method, the algebraic method, and the elimination method.

## Solving Linear Equations in One Variable

To solve a linear equation in one variable, follow these steps:

1. Isolate the variable: Move all the constants to one side of the equation and the variable to the other side.
2. Combine like terms: Combine any terms on the same side of the equation that have the same variable.
3. Solve for the variable: Divide both sides of the equation by the coefficient of the variable.
4. Check your answer: Substitute the solution back into the original equation and make sure that both sides are equal.

Example: Solve the following linear equation in one variable:

``````2x + 3 = 8
``````

Solution:

1. Isolate the variable:
``````2x = 5
``````
1. Combine like terms:
``````x = 5/2
``````
1. Solve for the variable:
``````x = 2.5
``````
``````2(2.5) + 3 = 8
``````
``````5 + 3 = 8
``````
``````8 = 8
``````

Therefore, the solution to the equation is x = 2.5.

## Solving Linear Equations in Two Variables

To solve a linear equation in two variables, follow these steps:

1. Rewrite the equations in slope-intercept form: This will make it easier to compare the equations and find the solution.
2. Compare the equations: If the equations have different slopes, then they will intersect once and have one solution. If the equations have the same slope and the same y-intercept, then they will overlap completely and have infinitely many solutions. If the equations have the same slope and different y-intercepts, then they will be parallel and have no solution.
3. Solve for the solution: If the equations have one solution, you can use the substitution method or elimination method to solve for the x- and y-values.

Example: Solve the following system of linear equations in two variables:

``````y = 2x + 3
y = x + 5
``````

Solution:

1. Rewrite the equations in slope-intercept form:
``````y = 2x + 3
y = x + 5
``````
1. Compare the equations:

The equations have different slopes, so they will intersect once and have one solution.

1. Solve for the solution:

We can use the substitution method to solve for the solution. Substitute the first equation into the second equation:

``````2x + 3 = x + 5
``````

Solve for x:

``````x = 2
``````

Substitute x = 2 into the first equation:

``````y = 2(2) + 3
``````
``````y = 7
``````

Therefore, the solution to the system of equations is x = 2 and y = 7.

## Conclusion

Solving linear equations is an essential skill in mathematics. Linear equations are used in many different fields, including science, engineering, and business. By understanding how to solve linear equations, you will be able to solve a variety of problems in these fields.

## FAQs

### Q: What is the difference between a linear equation and a quadratic equation?

A: A linear equation is an equation of the first degree, meaning that the highest exponent of any variable is 1. A quadratic equation is an equation of the second degree, meaning that the highest exponent of any variable is 2.

### Q: What is the best method for solving linear equations?

A: The best method for solving linear equations depends on the complexity of the equation. For simple linear equations, the algebraic method is usually the quickest and easiest. For more complex linear equations, the elimination method or graphical method may be more appropriate.

### Q: How do I solve a system of linear equations?

A: There are two main methods for solving a system of linear equations: the substitution method and the elimination method.