Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
1. Equations & Inequalities
Linear Equations
Problem 94
Textbook Question
Solve the equations containing absolute value in Exercises 94–95. |2x+1| = 7
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Step 1: The absolute value equation |2x+1| = 7 can be rewritten as two separate equations: 2x+1 = 7 and 2x+1 = -7. This is because the absolute value of a number is always positive, so the expression inside the absolute value can be either positive or negative.
Step 2: Solve the first equation 2x+1 = 7 for x. To do this, subtract 1 from both sides of the equation to isolate the term with x, then divide by 2 to solve for x.
Step 3: Solve the second equation 2x+1 = -7 for x. Similarly, subtract 1 from both sides of the equation to isolate the term with x, then divide by 2 to solve for x.
Step 4: The solutions to the original equation |2x+1| = 7 are the solutions to both equations from steps 2 and 3.
Step 5: Always check your solutions by substituting them back into the original equation to make sure they are correct.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Absolute Value
Absolute value measures the distance of a number from zero on the number line, regardless of direction. It is denoted by vertical bars, such as |x|. For example, |3| = 3 and |-3| = 3, indicating that both 3 and -3 are three units away from zero.
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Equations with Absolute Value
When solving equations that involve absolute values, it is essential to consider both the positive and negative scenarios. For the equation |2x + 1| = 7, this means setting up two separate equations: 2x + 1 = 7 and 2x + 1 = -7. Each equation must be solved independently to find all possible solutions.
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Solution Sets
A solution set is the collection of all values that satisfy a given equation. In the context of absolute value equations, it is important to check each potential solution to ensure it meets the original equation. For the example |2x + 1| = 7, the solutions must be verified to confirm they are valid.
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