1. **Problem:** Calculate $\frac{5}{7} - \frac{1}{4}$. 2. **Formula:** To subtract fractions, find a common denominator and subtract the numerators. 3. **Work:** Find the least common denominator (LCD) of 7 and 4, which is 28. Convert each fraction: $$\frac{5}{7} = \frac{5 \times 4}{7 \times 4} = \frac{20}{28}$$ $$\frac{1}{4} = \frac{1 \times 7}{4 \times 7} = \frac{7}{28}$$ Subtract: $$\frac{20}{28} - \frac{7}{28} = \frac{20 - 7}{28} = \frac{13}{28}$$ 4. **Answer:** $$\boxed{\frac{13}{28}}$$