What is the equation of the line shown in the graph?

Slope intercept form: y=mx+b, m=slope=rise/run, b=y-intercept when x=0

Line is decreasing from left to right, the slope is negative.
From point (2,-4) to (-3,1) is a rise 6 and run left 6
Slope=-6/6=-1

Look on the line for x=0 to find y-intercept, y-intercept is -2

Equation of the line is:
y=mx+b
y=-x-2

How many people are we starting with? i will answer it's just i need to divide 8 by the total amount of people to get how many tables

270 books in each shelves