## 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.

Problem 1.4a:

Solution: Multiply both sides by 42, the smallest number that 3, 7, 2, and 21 divides into evenly.

Simplify:

Subtract 21x from both sides of the equation:

Subtract 30 from both sides of the equation:

Divide both sides by 7:

Check the solution by substituting 2 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:
• Left Side:
• Right Side:
Since the left side of the original equation equals the right side of the original equation when 2 substituted for x, then x=2 is the correct answer.

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=2.

If you would like to review the solution to problem 1.4b, click on solution

If you would like to go back to the problem page, click on problem.

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