Consider the diagram.
What is the length of segment AB?

7
9
18
25

9

Step-by-step explanation:

Since sides AB and BC are congruent as marked by the congruency lines, they must have equal length. Therefore, AB must also have length 9. Hope this helps!

it is b)

hope this : )

step-by-step explanation:

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value