Answer
A: (1,7.5)
b:(0,6)
c: because the graph is linear graph and have a constant rate of change/ slope which is -1.5
Step-by-step explanation:
Basically, the question is asking, what will happen if we increase 9 by 30%?
first, what is 30% of 9?

So, the increase will be by 2.7 days,
So the total amount will be 9+2.7=11.7 - this is the correct answer.
Answer:
y = -3x + 150
Step-by-step explanation:
2 points on the graph:
(30, 60) and (40, 30)
Slope:
m=(y2-y1)/(x2-x1)
m=(30 - 60)/(40 - 30)
m= (-30)/10
m= -3
Slope-intercept:
y - y1 = m(x - x1)
y - 60 = -3(x - 30)
y - 60 = -3x + 90
y = -3x + 150