The rule for rewriting an absolute value equation without absolute value bars can be extended to equations with two sets of absolute value bars: If u and v represent algebraic expressions, then |u| = |v| is equivalent to u = v or u = - v. Use this to solve the equations in Exercises 77–84.
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
The Square Root Property
Problem 79
Textbook Question
Solve each equation. (x-3)2/5 = 4
Verified step by step guidance1
Start with the given equation: \( (x-3)^{\frac{2}{5}} = 4 \). Our goal is to solve for \(x\).
To eliminate the fractional exponent, raise both sides of the equation to the reciprocal power of \(\frac{2}{5}\), which is \(\frac{5}{2}\). This gives: \(\left((x-3)^{\frac{2}{5}}\right)^{\frac{5}{2}} = 4^{\frac{5}{2}}\).
Simplify the left side using the property of exponents \(\left(a^{m}\right)^{n} = a^{mn}\), so \( (x-3)^{\frac{2}{5} \times \frac{5}{2}} = (x-3)^1 = x-3 \).
Now the equation is \( x - 3 = 4^{\frac{5}{2}} \). Next, express \$4^{\frac{5}{2}}\( as \)\left(4^{\frac{1}{2}}\right)^5\( or \)\left(\sqrt{4}\right)^5$ to simplify the right side.
Finally, solve for \(x\) by adding 3 to both sides: \( x = 3 + 4^{\frac{5}{2}} \). This gives the solution for \(x\).
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
1mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rational Exponents
Rational exponents represent roots and powers simultaneously. For example, an exponent of 2/5 means raising the base to the power 2 and then taking the fifth root, or vice versa. Understanding how to manipulate these exponents is essential for solving equations involving fractional powers.
Recommended video:
Guided course
Rational Exponents
Isolating the Variable Expression
Before solving, isolate the expression with the variable on one side of the equation. This step simplifies the equation and prepares it for applying inverse operations, such as raising both sides to a reciprocal power to eliminate the rational exponent.
Recommended video:
Guided course
Radical Expressions with Variables
Checking for Extraneous Solutions
When solving equations with rational exponents, especially involving even roots, some solutions may not satisfy the original equation. Substituting solutions back into the original equation ensures only valid answers are accepted.
Recommended video:
Restrictions on Rational Equations
Watch next
Master Solving Quadratic Equations by the Square Root Property with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice
Textbook Question
516
views
