Answer:A directed graph is a graph that is directed and without cycles connecting the other edges.
Explanation:
I'm assuming you are referring to Excel. There are a few ways to add A1 and B1.
First you could use '=SUM(A1+B1)'
You could also use '=SUM(A1:B1)' which adds the values of all the cells between A1 and B1, but since they are next to each other, this would work.
You could also use '=SUM(A1,B1)' where you list all the cells you want to add with commas in between.
