Yes because 9+4 = 13 and if you plug in the y and x it turns out true
I hope this helps you
x'=1 y'=4 slope = -3
slope. (x'-x)=y'-y
-3. (1-x)=4-y
-3+3x=4-y
y=4+3-3x
y=7-3x
Answer:
a. 
b. 
Step-by-step explanation:
First, we need tot find a general expression for the amount of caffeine remaining in the body after certain time. As the problem states that every hour x percent of caffeine leaves the body, we must substract that percentage from the initial quantity of caffeine, by each hour passing. That expression would be:

Then, to find the amount of caffeine metabolized per hour, we need to differentiate the previous equation. Following the differentiation rules we get:

The rate is negative as it represents the amount of caffeine leaving the body at certain time.
Answer:
15.71m
Step-by-step explanation:
circumference of a circle = 2πr
where r = 2.5m
where π = 3.142
we have,
2*3.142*2.5 = 15.71m
therefore the circumference of a circle with a radius 2.5m = 15.71 m