Final answer:
To obtain a common denominator for 2/7 and 1/4, calculate the LCM of 7 and 4, which is 28. Rewrite 2/7 as 8/28 and 1/4 as 7/28, so they both have a common denominator of 28.
Step-by-step explanation:
To find a common denominator for the fractions 2/7 and 1/4, you need to find a number that both 7 and 4 can divide into evenly. This number is typically the least common multiple (LCM) of the two denominators. In this case, the LCM of 7 and 4 is 28. To convert each fraction to an equivalent fraction with a denominator of 28, multiply the numerator and the denominator of 2/7 by 4 (to get 8/28) and multiply the numerator and the denominator of 1/4 by 7 (to get 7/28).
So, we rewrite the fractions as:
- 2/7 becomes 8/28
- 1/4 becomes 7/28
Now, both fractions have a common denominator of 28, and they can be easily compared or added together.