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Ch. P - Fundamental Concepts of Algebra
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514당신이 사용하는 게 아니라요?교과서 변경
1장, 문제 51

Rationalize the denominator. 752\(\frac{7}{\sqrt{5}\) - 2}

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Identify the expression to rationalize: \(\frac{7}{\sqrt{5} - 2}\), where the denominator contains a radical.
To rationalize the denominator, multiply both the numerator and the denominator by the conjugate of the denominator. The conjugate of \(\sqrt{5} - 2\) is \(\sqrt{5} + 2\).
Set up the multiplication: \(\frac{7}{\sqrt{5} - 2} \times \frac{\sqrt{5} + 2}{\sqrt{5} + 2}\).
Multiply the numerators: \(7 \times (\sqrt{5} + 2)\), and multiply the denominators using the difference of squares formula: \((\sqrt{5})^2 - (2)^2\).
Simplify the denominator to \(5 - 4\), and write the expression as \(\frac{7(\sqrt{5} + 2)}{1}\), which completes the rationalization process.

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주요 개념

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

Rationalizing the Denominator

Rationalizing the denominator involves eliminating any irrational numbers, such as square roots, from the denominator of a fraction. This is done to simplify the expression and make it easier to work with or interpret.
추천 영상:
02:58
Rationalizing Denominators

Conjugates of Binomials

The conjugate of a binomial expression a + b is a - b, and vice versa. Multiplying a binomial by its conjugate results in a difference of squares, which helps eliminate square roots in the denominator.
추천 영상:
05:33
Complex Conjugates

Difference of Squares Formula

The difference of squares formula states that (a + b)(a - b) = a² - b². This property is used when multiplying by the conjugate to remove radicals from the denominator by turning it into a rational number.
추천 영상:
04:14
Special Products - Square Formulas