Kerille is reading a book at the rate of 4.5 pages per minute. what ordered pair on a graph of his reading rate would represent the number of minutes it will take him to read 90 pages?

This is a linear equation y = mx, where:
m= slope or reading rate:
x = the number of minutes
y = the number of pages read.

So the equation becomes: y = 4.5.x
How many minutes it will take to read 90 pages (y):
90 = 4.5.x    or x = 90/4.5  and x = 20 minutes
So the ordered pair will be (20,90)