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
- 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.
Subtract 10x 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
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.
- Left Side:
- Right Side:
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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