Answer:
A) 0
Step-by-step explanation:
15/21 simplifies to 5/7. 5/7-5/7 (itself) is 0.
0
= [tex]\frac{5}{7}-\frac{5}{7}[/tex]
= [tex]\frac{5-5}{7}[/tex]
= [tex]\frac{0}{7}[/tex]
= [tex]0[/tex]
