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 \( \frac{3}{3} \) - \( \frac{7}{7} \)?
| 1 \( \frac{1}{4} \) | |
| \( \frac{1}{21} \) | |
| \( \frac{8}{21} \) | |