Answer:
B. y - 35 = 2(x - 10)
Step-by-step explanation:
The height of the plant, y, after x days could be modeled by the equation
<h3>y-y0=k(x-xo) (1)
,</h3><h3>
where y0 was the initial height at 'x0'th. day, and k is the constant of proportionality.</h3><h3>
From equation (1), k could be evaluated as follows:</h3><h3>
k=(y-y0)/(x-x0) </h3><h3>
From the problem statement, we may determine k by plugging in the given values, e.g. y0= 35, x0=10, y=55, x=20.</h3><h3>
Thus,</h3><h3>
k=(55-35)/(20-10)=2</h3><h3>
Therefore, the model equation becomes</h3><h3>
y-35=2(x-10)</h3><h3>
</h3>
Your answer would be 23.85 but I presume they rounded up so it would be 23.9
Let 
be the dimensions of the rectangle. We know the equations for both area and perimeter:
So, we have the following system:
From the second equation, we can deduce
Plug this in the first equation to get
Refactor as
And solve with the usual quadratic formula to get
Both solutions are feasible, because they're both positive.
If we chose the positive solution, we have
If we choose the negative solution, we have
So, we're just swapping the role of 
and 
. The two dimensions of the rectangle are 
and 
