§ 1.4 Solving Linear Equations. Blitzer, Algebra for College Students, 6e – Slide #2 Section 1.4...
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Transcript of § 1.4 Solving Linear Equations. Blitzer, Algebra for College Students, 6e – Slide #2 Section 1.4...
§ 1.4
Solving Linear Equations
Blitzer, Algebra for College Students, 6e – Slide #2 Section 1.4
Linear Equations
Definition of a Linear Equation
A linear equation in one variable x is an equation that can be written in the form ax + b = 0, where a and b are real numbers and a is not equal to 0.
An example of a linear equation in x is 4x + 2 = 6. Linear equations in x are first degree equations in the variable x.
Blitzer, Algebra for College Students, 6e – Slide #3 Section 1.4
Properties of Equality
Property Definition
Addition Property of Equality
The same real number or algebraic expression may be added to both sides of an equation without changing the equation’s solution set.
Multiplication Property of Equality
The same nonzero real number may multiply both sides of an equation without changing the equation’s solution set.
Blitzer, Algebra for College Students, 6e – Slide #4 Section 1.4
Solving Linear Equations
Solving a Linear Equation
1) Simplify the algebraic expressions on each side.
2) Collect all the variable terms on one side and all the numbers, or constant terms, on the other side
3) Isolate the variable and solve.
4) Check the proposed solution in the original equation.
Blitzer, Algebra for College Students, 6e – Slide #5 Section 1.4
Solving Linear Equations
EXAMPLEEXAMPLE
SOLUTIONSOLUTION
Solve 4x + 2 = 10.
Blitzer, Algebra for College Students, 6e – Slide #6 Section 1.4
Solving Linear Equations
EXAMPLEEXAMPLE
SOLUTIONSOLUTION
Solve 6x -7 = 3x + 8.
Blitzer, Algebra for College Students, 6e – Slide #7 Section 1.4
Solving Linear Equations
EXAMPLEEXAMPLE
SOLUTIONSOLUTION
Solve: 5 - 3x + 4x = 1 - 7x + 12.
Blitzer, Algebra for College Students, 6e – Slide #8 Section 1.4
Categorizing an Equations
Type of Equations Definitions
Identity An equation that is true for all real numbers
Conditional An equation that is not an identity but is true for at least one real number
Inconsistent
(contradiction)
An equation that is not true for any real number
Blitzer, Algebra for College Students, 6e – Slide #9 Section 1.4
Categorizing an Equation
EXAMPLEEXAMPLE
SOLUTIONSOLUTION
Solve and determine whether the equation is an identity, a conditional equation or an inconsistent equation.
5 + 4x = 9x + 5
Blitzer, Algebra for College Students, 6e – Slide #10 Section 1.4
Categorizing an Equation
EXAMPLEEXAMPLE
SOLUTIONSOLUTION
Solve and determine whether the equation is an identity, a conditional equation or an inconsistent equation.
5 – (2x – 4) = 2(x +1) - 4x