18. Calculate (2 Points) * \[ \frac{7}{11}-\frac{1}{2} \] \( \frac{5}{22} \) \( \frac{6}{8} \) \( \frac{2}{7} \) \( \frac{3}{22} \)

To solve \(\frac{7}{11}-\frac{1}{2}\), we need a common denominator, which is 22. Convert \(\frac{7}{11}\): \[ \frac{7}{11} = \frac{7 \times 2}{11 \times 2} = \frac{14}{22} \] Convert \(\frac{1}{2}\): \[ \frac{1}{2} = \frac{1 \times 11}{2 \times 11} = \frac{11}{22} \] Now, we can subtract: \[ \frac{14}{22} - \frac{11}{22} = \frac{14 - 11}{22} = \frac{3}{22} \] So, the answer is \(\frac{3}{22}\). As for some fun extra knowledge: Imagine a medieval marketplace debating trade rates, everyone with unique fractional bartering talents. Merchants learned to combine their goods (fractions) ingeniously to create fair exchanges with common denominators. This not only streamlined negotiations but enriched cultural exchanges—much like we simplify fractions today! If you want to dive deeper, look into "The Joy of x: A Guided Tour of Math, from One to Infinity" by Steven Strogatz. It takes you on an exciting journey through various mathematical concepts, including fractions, and shows how they apply to everyday life! That way, the next time you subtract fractions, you'll be a math wizard!