Answer :
Answer:
you basically do the same things just backwards
Step-by-step explanation:
for example 9+9=18 well to double check your work all you do is flip to equation 18-9=9
Answer:
you basically do the same things just backwards
Step-by-step explanation:
for example 9+9=18 well to double check your work all you do is flip to equation 18-9=9