Divide the sum of , 5/21 by their differences 4/7

17/7

17/7 is the correct answer!

17/7 is the correct answer.

To divide the sum of two fractions by their difference, you need to follow these steps:

Step 1: Find the sum of the two fractions
Step 2: Find the difference of the two fractions
Step 3: Divide the sum by the difference

Let's apply these steps to the given fractions, 5/21 and 4/7.

Step 1: Find the sum of the two fractions
To find the sum, add the numerators of the fractions while keeping the same denominator:
5/21 + 4/7 = (5 + 12) / 21 = 17/21

The sum of 5/21 and 4/7 is 17/21.

Step 2: Find the difference of the two fractions
To find the difference, subtract the second fraction from the first fraction:
5/21 - 4/7 = (5/21) - (12/21) = (5 - 12)/21 = -7/21

The difference between 5/21 and 4/7 is -7/21.

Step 3: Divide the sum by the difference
Divide the sum found in Step 1 by the difference found in Step 2:
(17/21) / (-7/21) = (17/21) * (21/-7) = 17/-7 = -17/7

Therefore, the result of dividing the sum of 5/21 by their differences 4/7 is -17/7.

(4/7 + 5/21)

------------------- = 17/5
(4/7 - 5/21)

-17/7