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:
21.5cm
Step-by-step explanation:
41,572=4/3*pi*r^3
Work backwards to solve for r
Answer:
E
Step-by-step explanation:
I’m not 100% sure, but I believe it’s A and C
Answer:
y = -7(x +1)² +35
Step-by-step explanation:
The given quadratic equation has two parameters you are asked to find. When you fill in the given point values, the result is two linear equations in the two unknown parameters. You can solve these equations in any of the usual ways.
__
<h3>equation for point (1, 7)</h3>
y = a(x +1)² +k
7 = a(1 +1)² +k
7 = 4a +k
<h3>equation for point (2, -28)</h3>
-28 = a(2 +1)² +k
-28 = 9a +k
<h3>solution</h3>
The first equation can be subtracted from the second equation to eliminate the k variable. (This is solving by <em>elimination</em>.)
(-28) -(7) = (9a +k) -(4a +k)
-35 = 5a . . . . . . . . simplify
-7 = a . . . . . . . . divide by 5
Using the first equation, we can find k.
7 -4a = k . . . . . subtract 4a
7 -4(-7) = k . . . . substitute for 'a'
35 = k
The parameter values are a = -7, and k = 35. The quadratic equation is ...
y = -7(x +1)² +35
