The temperature decreases 5°F every hour
Answer:
y = - 
Step-by-step explanation:
Given y varies inversely with x then the equation relating them is
y =
← k is the constant of variation
To find k use the condition y = 7 when x = - 4, then
7 =
( multiply both sides by - 4 )
- 28 = k
y =
← equation of variation
When x = 5 , then
y =
= - 
Answer:
The graph in the attached figure
Step-by-step explanation:
we have

This is a exponential function of the form

where
a is the initial value or the y-intercept
b is the base of the exponential function
If b>1 then is a exponential growth function
If b<1 then is a exponential decay function
In this problem
The y-intercept is equal to
For x=0

The y-intercept is the point (0,1)
so


The value of b is greater than 1
so
Is a growth function
To plot the graph create a table with different values of x and y
For x=-1
f(x)=2^-1=0.5
point (-1,0.5)
For x=1

point (1,2)
For x=2

point (2,4)
For x=3

point (3,8)
For x=4
f(x)=2^4=16
point (4,16)
Plot the y-intercept and the other points and connect them to graph the exponential function
Note that as x increases the value of y increases (exponential growth function)
The graph in the attached figure
Pick any value in the y column of the table. I'm going to pick 81. Divide the value you picked by the previous y value, which in my case would be 9
Dividing the values gives: 81/9 = 9
So the base is 9. We multiply each y value by 9 to get the next y value
Eg: to go from 1/81 to 1/9, we multiply by 9. Same for 1/9 to 1, and so on.
Answer: Choice B) 9
Note: This trick only works because x is increasing by 1 each time
Bob hiked 16*12=192 miles total.
Lola hiked 14*16=224 miles total.
Lola hiked 224-192=32 more miles than Bob. Girl power!
Hope this helps!