What is the result of 6/21 - 5/7?

To solve the expression ( 6/21 - 5/7 ), it is essential first to have a common denominator to facilitate the subtraction of the two fractions.

The fraction ( 6/21 ) can be simplified. ( 6/21 ) simplifies to ( 2/7 ) since both the numerator and the denominator can be divided by 3.

Now, we rewrite the expression:

[

2/7 - 5/7

]

Since both fractions now share the same denominator (7), we can directly subtract the numerators:

[

(2 - 5)/7 = -3/7

]

To answer the original question, we simplify -3/7. To convert -3/7 to a form that may match the choices, we observe that this fraction does not equal -1/3, -9/21, or 0. However, -3/7 can also be expressed as -9/21 because:

[

-3/7 = -9/21 \quad (by ; multiplying ; both ; numerator ; and ; denominator ; by ; 3)

]

Thus, the correct result of ( 6/