Question

1. \\(\frac{4}{a} - \frac{7}{b} =\\)

\\(\bigcirc\\) \\(\frac{4a - 7b}{ab}\\)

\\(\bigcirc\\) \\(\frac{-3}{ab}\\)

\\(\bigcirc\\) \\(\frac{4b - 7a}{ab}\\)

\\(\bigcirc\\) \\(\frac{-3}{a + b}\\)

Explanation:

Find a common denominator

$$ \text{LCD} = ab $$

Convert each fraction

$$ \frac{4}{a} = \frac{4b}{ab},\quad \frac{7}{b} = \frac{7a}{ab} $$

Subtract the numerators

$$ \frac{4b}{ab} - \frac{7a}{ab} = \frac{4b - 7a}{ab} $$

Answer:

• (A) \(\frac{4a - 7b}{ab}\)
• (B) \(\frac{-3}{ab}\)
• (C) \(\frac{4b - 7a}{ab}\) (Correct answer)
• (D) \(\frac{-3}{a + b}\)