Elementary Algebra 2e

Chapter 1 Foundations
15 Topics
Introduction
1.1 Introduction to Whole Numbers
1.2 Use the Language of Algebra
1.3 Add and Subtract Integers
1.4 Multiply and Divide Integers
1.5 Visualize Fractions
1.6 Add and Subtract Fractions
1.7 Decimals
1.8 The Real Numbers
1.9 Properties of Real Numbers
1.10 Systems of Measurement
Chapter Review Key Terms
Key Concepts
Review Exercises
Practice Test
Chapter 2 Solving Linear Equations and Inequalities
12 Topics
Introduction
2.1 Solve Equations Using the Subtraction and Addition Properties of Equality
2.2 Solve Equations using the Division and Multiplication Properties of Equality
2.3 Solve Equations with Variables and Constants on Both Sides
2.4 Use a General Strategy to Solve Linear Equations
2.5 Solve Equations with Fractions or Decimals
2.6 Solve a Formula for a Specific Variable
2.7 Solve Linear Inequalities
Key Terms
Key Concepts
Review Exercises
Practice Test
Chapter 3 Math Models
11 Topics
Introduction
3.1 Use a Problem-Solving Strategy
3.2 Solve Percent Applications
3.3 Solve Mixture Applications
3.4 Solve Geometry Applications: Triangles, Rectangles, and the Pythagorean Theorem
3.5 Solve Uniform Motion Applications
3.6 Solve Applications with Linear Inequalities
Key Terms
Key Concepts
Review Exercises
Practice Test
Chapter 4 Graphs
12 Topics
Introduction
4.1 Use the Rectangular Coordinate System
4.2 Graph Linear Equations in Two Variables
4.3 Graph with Intercepts
4.4 Understand Slope of a Line
4.5 Use the Slope-Intercept Form of an Equation of a Line
4.6 Find the Equation of a Line
4.7 Graphs of Linear Inequalities
Chapter Review
Key Terms
Review Exercises
Practice Test
Chapter 5 Systems of Linear Equations
5 Topics
Introduction
5.1 Solve Systems of Equations by Graphing
5.3 Solve Systems of Equations by Elimination
5.5 Solve Mixture Applications with Systems of Equations
5.4 Solve Applications with Systems of Equations
Chapter 6 Polynomials
12 Topics
Introduction
6.1 Add and Subtract Polynomials
6.2 Use Multiplication Properties of Exponents
6.3 Multiply Polynomials
6.4 Special Products
6.5 Divide Monomials
6.6 Divide Polynomials
6.7 Integer Exponents and Scientific Notation
Key Terms
Key Concepts
Review Exercises
Practice Test
7 Factoring
11 Topics
Introduction
7.1 Greatest Common Factor and Factor by Grouping
7.2 Factor Trinomials of the Form x2+bx+c
7.3 Factor Trinomials of the Form ax2+bx+c
7.4 Factor Special Products
7.5 General Strategy for Factoring Polynomials
7.6 Quadratic Equations
Key Terms
Key Concepts
Review Exercises
Practice Test
8 Rational Expressions and Equations
14 Topics
Introduction
8.1 Simplify Rational Expressions
8.2 Multiply and Divide Rational Expressions
8.3 Add and Subtract Rational Expressions with a Common Denominator
8.4 Add and Subtract Rational Expressions with Unlike Denominators
8.5 Simplify Complex Rational Expressions
8.6 Solve Rational Equations
8.7 Solve Proportion and Similar Figure Applications
8.8 Solve Uniform Motion and Work Applications
8.9 Use Direct and Inverse Variation
Key Terms
Key Concepts
Review Exercises
Practice Test
9 Roots and Radicals
13 Topics
Introduction
9.1 Simplify and Use Square Roots
9.2 Simplify Square Roots
9.3 Add and Subtract Square Roots
9.4 Multiply Square Roots
9.5 Divide Square Roots
9.6 Solve Equations with Square Roots
9.7 Higher Roots
9.8 Rational Exponents
Key Terms
Key Concepts
Review Exercises
Practice Test
10 Quadratic Equations
10 Topics
Introduction
10.1 Solve Quadratic Equations Using the Square Root Property
10.2 Solve Quadratic Equations by Completing the Square
10.3 Solve Quadratic Equations Using the Quadratic Formula
10.4 Solve Applications Modeled by Quadratic Equations
10.5 Graphing Quadratic Equations in Two Variables
Key Terms
Key Concepts
Review Exercises
Practice Test
Answer Key
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Index
Quiz
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2.4 Use a General Strategy to Solve Linear Equations

Elementary Algebra 2e Chapter 2 Solving Linear Equations and Inequalities 2.4 Use a General Strategy to Solve Linear Equations

Learning Objectives

By the end of this section, you will be able to:

  • Solve equations using a general strategy
  • Classify equations

Solution

This figure is a table that has three columns and five rows. The first column is a header column, and it contains the names and numbers of each step. The second column contains further written instructions. The third column contains math. On the top row of the table, the first cell on the left reads: “Step 1. Simplify each side of the equation as much as possible.” The text in the second cell reads: “Use the Distributive Property. Notice that each side of the equation is simplified as much as possible.” The third cell contains the equation negative 6 times x plus 3, where x plus 3 is in parentheses, equals 24. Below this is the same equation with the negative 6 distributed across the parentheses: negative 6x minus 18 equals 24.
In the second row of the table, the first cell says: “Step 2. Collect all variable terms on one side of the equation.” In the second cell, the instructions say: “Nothing to do—all x’s are on the left side. The third cell is blank.
In the third row of the table, the first cell says: “Step 3. Collect constant terms on the other side of the equation. In the second cell, the instructions say: “To get constants only on the right, add 18 to each side. Simplify.” The third cell contains the same equation with 18 added to both sides: negative 6x minus 18 plus 18 equals 24 plus 18. Below this is the equation negative 6x equals 42.
In the fourth row of the table, the first cell says: “Step 4. Make the coefficient of the variable term equal to 1.” In the second cell, the instructions say: “Divide each side by negative 6. Simplify. The third cell contains the same equation divided by negative 6 on both sides: negative 6x over negative 6 equals 42 over negative 6, with “divided by negative 6” written in red on both sides. Below this is the answer to the equation: x equals negative 7.
In the fifth row of the table, the first cell says: “Step 5. Check the solution.” In the second cell, the instructions say: “Let x equal negative 7. Simplify. Multiply.” In the third cell, there is the instruction: “Check,” and to the right of this is the original equation again: negative 6 times x plus 3, with x plus 3 in parentheses, equal 24. Below this is the same equation with negative 7 substituted in for x: negative 6 times negative 7 plus 3, with negative 7 plus 3 in parentheses, might equal 24. Below this is the equation negative 6 times negative 4 might equal 24. Below this is the equation 24 equals 24, with a check mark next to it.
Type of equationWhat happens when you solve it?Solution
Conditional EquationTrue for one or more values of the variables and false for all other valuesOne or more values
IdentityTrue for any value of the variableAll real numbers
ContradictionFalse for all values of the variableNo solution

Table2.5

Self Check

ⓐ After completing the exercises, use this checklist to evaluate your mastery of the objective of this section.This is a table that has three rows and four columns. In the first row, which is a header row, the cells read from left to right: “I can…,” “confidently,” “with some help,” and “no-I don’t get it!” The first column below “I can…” reads: “solve equations using the general strategy for solving linear equations,” and “classify equations.” The rest of the cells are blank.

ⓑ On a scale of 1-10, how would you rate your mastery of this section in light of your responses on the checklist? How can you improve this?

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