Fractions must share a common denominator in order to be added or subtracted. The common denominator is the least common multiple of all the denominators.
What is \( \frac{2}{4} \) - \( \frac{9}{10} \)?
| 1 \( \frac{8}{20} \) | |
| 1 \( \frac{4}{20} \) | |
| -\(\frac{2}{5}\) | |
| \( \frac{2}{9} \) |