## SOLVING LINEAR EQUATIONS

**
Recall the following:
**

** A linear equation is a polynomial of degree 1.**** In order to solve for the unknown variable, you must isolate the
variable.**** In the order of operations, multiplication and division are
completed before addition and subtraction.
**

Example 3: Solve for x in the following equation.

Multiply both sides by the lowest common multiple of 3, 6, 9,
and 18, or 18.

Simplify:

Subtract 10*x* from both sides of the equation:

Subtract 15 from both sides of the equation:

Divide both sides by 2:

The answer is *x*=4.

Check the solution by substituting 4 in the original equation
for *x*. If the left side of the equation equals the right side of
the equation after the substitution, you have found the correct
answer.

- Left side:
- Right Side:

You can also check the answer with your calculator.
- Left Side:
- Right Side:

You can also check your answer by graphing
(left side of the
original equation minus the right side of the original equation). The
graph will cross the *x*-axis at *x*=3.5.

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**If you would like to test yourself by working some problems similar to this example, click on Problem**

**If you would like to go back to the equation Table of contents, click on Contents**.

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**
[Algebra]
[Trigonometry]
**** **
[Geometry]
[Differential Equations]
[Calculus]
[Complex Variables]
[Matrix Algebra]

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**Author:Nancy Marcus**

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