Answer:
From text
A)
A good scale to use for the y-axis is 500 for each square, starting from 14,000 to skip the irrelevant numbers less than 14,000. The numbers and range are very large, so a scale of 500 makes the y-axis about 10 squares high.
B)
A good interval to use for the y-axis is 500. Both 14,000 and 18,500 are multiples of 500.
From photo
a) I have never used point-slope form, but the equation in slope-intercept form is y = -3x + 30
Points on the graph are (3, 21) and (6, 12).
The slope is found with the equation m = (y2-y1)/(x2-x1)
m = (21-12)/(3-6)
m = 9/-3
m = -3
Sub a random point, (3,21) and m=-3 into slope-intercept form
y = mx + b
21 = -3 (3) + b
21 = -9 + b
Isolate b
b = 30
b) Initially, it took Scott 30 minutes to deliver his packages, the y-intercept. Everyday, the times decreased by 3 minutes, the slope.