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Ch. R - Review of Basic Concepts
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
1장, 문제 65a

Add or subtract, as indicated. (x + y)/(2x - y) - 2x/(y - 2x)

검증된 단계별 안내
1
Identify the two rational expressions to be combined: \(\frac{x + y}{2x - y}\) and \(\frac{2x}{y - 2x}\).
Notice that the denominators \(2x - y\) and \(y - 2x\) are very similar but not the same. Rewrite the second denominator to see the relationship: \(y - 2x = -(2x - y)\).
Rewrite the second fraction using this relationship: \(\frac{2x}{y - 2x} = \frac{2x}{-(2x - y)} = -\frac{2x}{2x - y}\).
Now the expression becomes \(\frac{x + y}{2x - y} - \left(-\frac{2x}{2x - y}\right)\), which simplifies to \(\frac{x + y}{2x - y} + \frac{2x}{2x - y}\) because subtracting a negative is addition.
Since both fractions have the same denominator \(2x - y\), combine the numerators over the common denominator: \(\frac{(x + y) + 2x}{2x - y}\). Then simplify the numerator by combining like terms.

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주요 개념

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

Finding a Common Denominator

To add or subtract rational expressions, you must first find a common denominator. This involves identifying the least common denominator (LCD) that both denominators can divide into, allowing the expressions to be combined into a single fraction.
추천 영상:
02:58
Rationalizing Denominators

Simplifying Rational Expressions

Simplifying rational expressions involves factoring numerators and denominators and reducing common factors. This step is crucial after combining fractions to express the result in its simplest form.
추천 영상:
05:07
Simplifying Algebraic Expressions

Handling Negative Signs and Equivalent Denominators

Recognizing that denominators like (2x - y) and (y - 2x) are negatives of each other helps in rewriting expressions for easier addition or subtraction. Properly managing negative signs ensures accurate combination of terms.
추천 영상:
02:58
Rationalizing Denominators