| 3/4 - 2/5 |
Reason: |
| Denominator = 20 |
The lowest common multiple of 4 and 5 is 20. Our denominator will be 20. |
| 3/4 becomes 15/20 |
Change 3/4 to 15/20 by multiplying above and below the line by 5. |
| 2/5 becomes 8/20 |
Change 2/5 to 8/20 by multiplying above and below the line by 4. |
| = 15/20 - 8/20 |
We now have fractions with the same denominator. |
| = 7/20 |
Keep the denominator 20. Subtract 8 from 15 to get the new numerator 7. |