Answer:
A line perpendicular to another has a slope that is the negative reciprocal of the slope of the other line. The negative reciprocal of the original line is –2, and is thus the slope of its perpendicular line.
Step-by-step explanation:
The answer is b, since that's the only other function there that involves using absolute value
There are 150 students in Hannah's school.
Sum of books donated by the students =b.
Average books donated by each student =
It is given Hannah donated 3 times as many books each student donated.
Number of books donated by Hannah= 
The expression of the number of books donated by Hannah= 