To see how to solve an equation that involves the absolute value of a quadratic polynomial, such as | x2 - x | = 6, work Exercises 83–86 in order. For x2 - x to have an absolute value equal to 6, what are the two possible values that x may assume? (Hint: One is positive and the other is negative.)
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
Linear Inequalities
Problem 86
Textbook Question
Solve each inequality. Give the solution set using interval notation.
Verified step by step guidance1
Start by expanding the expressions on both sides of the inequality: expand \$7x - 2(x - 3)\( and \)5(2 - x)$.
Distribute the multiplication over addition/subtraction inside the parentheses: \$7x - 2x + 6 \leq 10 - 5x$.
Combine like terms on the left side: \((7x - 2x)\) becomes \$5x\(, so the inequality is \)5x + 6 \leq 10 - 5x$.
Add \$5x\( to both sides to get all \)x\( terms on one side: \)5x + 5x + 6 \leq 10\(, which simplifies to \)10x + 6 \leq 10$.
Subtract 6 from both sides to isolate the term with \(x\): \$10x \leq 4\(, then divide both sides by 10 to solve for \)x$.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Solving Linear Inequalities
Solving linear inequalities involves isolating the variable on one side to find the range of values that satisfy the inequality. Similar to equations, operations like addition, subtraction, multiplication, and division are used, but special care is needed when multiplying or dividing by negative numbers, as this reverses the inequality sign.
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Distributive Property
The distributive property allows you to multiply a single term across terms inside parentheses, such as a(b + c) = ab + ac. This is essential for simplifying expressions on both sides of the inequality before solving, ensuring all terms are combined correctly.
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Multiply Polynomials Using the Distributive Property
Interval Notation
Interval notation is a concise way to represent solution sets of inequalities using intervals. It uses parentheses for values not included (open intervals) and brackets for values included (closed intervals), clearly showing the range of solutions on the number line.
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