Answer:
Part A) The proportional equation is
Part B) 8 hours of training
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or
Let
c -----> the cost to hire a dog
h ----> the amount of time in hours
The linear equation is equal to
Sue spent $660 on 12 hours of obedience training for her dog Muffin
Find the value of k (constant of proportionality)

substitute the values

therefore
The linear equation is
For 
Find the value of h
substitute in the equation and solve for h
Answer:
r = - 
Step-by-step explanation:
Given that r varies inversely as t , then the equation relating them is
r =
← k is the constant of variation
To find k use the condition t = - 6 when r = - 2, then
- 2 =
( multiply both sides by - 6 )
12 = k, thus
r =
← equation of variation
when t = - 7, then
r =
= - 
Answer:
310.86ft²
Step-by-step explanation:
30/2 = 15
3.14*15² = 706.5
30+3+3 = 36
36/2 = 18
3.14*18² = 1017.36
1017.36 - 706.5 = 310.86
Hope it helps
the light bulb uses 8100 total watts