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Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
2장, 문제 67

Solve each equation. (x-4)2/5 = 9

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Start with the given equation: \( (x-4)^{\frac{2}{5}} = 9 \).
To eliminate the fractional exponent, raise both sides of the equation to the reciprocal power, which is \( \frac{5}{2} \), so you get: \( \left((x-4)^{\frac{2}{5}}\right)^{\frac{5}{2}} = 9^{\frac{5}{2}} \).
Simplify the left side using the property of exponents \( (a^{m})^{n} = a^{mn} \), which gives: \( (x-4)^{\frac{2}{5} \times \frac{5}{2}} = (x-4)^1 = x-4 \).
Now the equation is \( x - 4 = 9^{\frac{5}{2}} \). Calculate \( 9^{\frac{5}{2}} \) by first finding the square root of 9, then raising the result to the 5th power.
Finally, solve for \( x \) by adding 4 to both sides: \( x = 9^{\frac{5}{2}} + 4 \).

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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

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 and interpret these exponents is essential for solving equations involving fractional powers.
추천 영상:
04:06
Rational Exponents

Isolating the Variable Expression

Before solving, isolate the expression containing the variable, such as (x - 4)^(2/5). This allows you to apply inverse operations, like raising both sides to the reciprocal power, to eliminate the rational exponent and simplify the equation for easier solving.
추천 영상:
06:44
Radical Expressions with Variables

Solving Equations with Even Powers

When an expression is raised to an even power, the equation may have two solutions: one positive and one negative. After isolating the base, consider both the positive and negative roots when solving for the variable to ensure all possible solutions are found.
추천 영상:
04:10
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