Math Problem Statement

a/b - b/a can be written as the product of two factors, and the sum of two factors is a/b + b/a

Solution

To solve the expression abba\frac{a}{b} - \frac{b}{a}, let's break it down step-by-step.

Step 1: Combine terms

We want to combine the two fractions, ab\frac{a}{b} and ba\frac{b}{a}, into a single expression. To do this, we first find a common denominator.

The least common denominator (LCD) of bb and aa is abab, so we rewrite both fractions:

ab=a2ab,ba=b2ab\frac{a}{b} = \frac{a^2}{ab}, \quad \frac{b}{a} = \frac{b^2}{ab}

Now subtract the two fractions:

abba=a2abb2ab=a2b2ab\frac{a}{b} - \frac{b}{a} = \frac{a^2}{ab} - \frac{b^2}{ab} = \frac{a^2 - b^2}{ab}

Step 2: Factor the numerator

Notice that a2b2a^2 - b^2 is a difference of squares, which can be factored as:

a2b2=(ab)(a+b)a^2 - b^2 = (a - b)(a + b)

So the expression becomes:

abba=(ab)(a+b)ab\frac{a}{b} - \frac{b}{a} = \frac{(a - b)(a + b)}{ab}

Thus, the expression abba\frac{a}{b} - \frac{b}{a} can indeed be written as the product of two factors: (ab)(a - b) and (a+b)(a + b), and the denominator is abab.

Step 3: Consider the sum of the factors

The sum of the two factors is:

ab+ba\frac{a}{b} + \frac{b}{a}

We follow a similar process to combine the two fractions:

ab+ba=a2ab+b2ab=a2+b2ab\frac{a}{b} + \frac{b}{a} = \frac{a^2}{ab} + \frac{b^2}{ab} = \frac{a^2 + b^2}{ab}

So the sum of the two factors is a2+b2ab\frac{a^2 + b^2}{ab}.

Conclusion:

  • abba\frac{a}{b} - \frac{b}{a} can be written as the product of two factors: (ab)(a+b)ab\frac{(a - b)(a + b)}{ab}.
  • The sum of the two factors ab+ba\frac{a}{b} + \frac{b}{a} is a2+b2ab\frac{a^2 + b^2}{ab}.

Let me know if you need more clarification or have further questions!


Here are 5 related questions:

  1. What is the difference of squares formula, and how does it simplify expressions?
  2. How do you simplify expressions involving fractions with different denominators?
  3. How can you factor other quadratic expressions, such as x2+6x+9x^2 + 6x + 9?
  4. What is the relationship between addition and subtraction of fractions with the same denominator?
  5. How would the expressions change if aa and bb were negative numbers?

Tip: Always look for patterns like the difference of squares or perfect square trinomials to simplify algebraic expressions!

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Math Problem Analysis

Mathematical Concepts

Algebra
Fractions
Difference of Squares
Factoring

Formulas

Difference of Squares: a^2 - b^2 = (a - b)(a + b)
Sum of fractions: a/b + b/a = (a^2 + b^2) / ab

Theorems

Difference of Squares

Suitable Grade Level

Grades 9-10