Below are monthly rents paid by 30 students who live off campus.

You have D dollars to buy fence to enclose a rectangular plot of land (see figure at right). The fence for the top and bottom co

alex41 [277]

The perimeter of the rectangular plot of land is given by the expression below

$P=2x+2y$

On the other hand, since the available money to buy fence is D dollars,

$\begin{gathered} D=4(2x)+3(2y) \\ \Rightarrow D=8x+6y \\ D\rightarrow\text{ constant} \end{gathered}$

Furthermore, the area of the enclosed land is given by

$A=xy$

Solving the second equation for x,

$\begin{gathered} D=8x+6y \\ \Rightarrow x=\frac{D-6y}{8} \end{gathered}$

Substituting into the equation for the area,

$\begin{gathered} A=(\frac{D-6y}{8})y \\ \Rightarrow A=\frac{D}{8}y-\frac{3}{4}y^2 \end{gathered}$

To find the maximum possible area, solve A'(y)=0, as shown below

$\begin{gathered} A^{\prime}(y)=0 \\ \Rightarrow\frac{D}{8}-\frac{3}{2}y=0 \\ \Rightarrow\frac{3}{2}y=\frac{D}{8} \\ \Rightarrow y=\frac{D}{12} \end{gathered}$

Therefore, the corresponding value of x is

$\begin{gathered} y=\frac{D}{12} \\ \Rightarrow x=\frac{D-6(\frac{D}{12})}{8}=\frac{D-\frac{D}{2}}{8}=\frac{D}{16} \end{gathered}$ <h2>Thus, the dimensions of the fence that maximize the area are x=D/16 and y=D/12.</h2><h2>As for the used money,</h2> $\begin{gathered} top,bottom:\frac{8D}{16}=\frac{D}{2} \\ Sides:\frac{6D}{12}=\frac{D}{2} \end{gathered}$ <h2>Half the money was used for the top and the bottom, while the other half was used for the sides.</h2>

7 0

11 months ago

What is the equation of the line? Please help

pentagon [3]

The second one 1/2x+2

3 0

2 years ago

I ONLY need 8c<br> Please show ALL STEPS

viktelen [127]

Answer:

8c

f(g(x)) = x^4 + 2x^3 - x

g(f(x)) = x^4 + 2x^3 + 2x^2 - x

Step-by-step explanation:

f(x) = x^2 - x ; g(x) = x^2 + x

f(g(x)) = (x^2 + x)^2 - (x^2 + x)

f(g(x)) = (x^2 + x)^2 - x^2 - x

f(g(x)) = (x^2 + x)(x^2 + x) - x^2 - x

f(g(x)) = x^4 + x^3 + x^3 + x^2 - x^2 - x

f(g(x)) = x^4 + 2x^3 - x

g(f(x)) = (x^2 - x)^2 + x^2 - x

g(f(x)) = (x^2 + x)(x^2 + x) + x^2 - x

g(f(x)) = x^4 + x^3 + x^3 + x^2 + x^2 - x

g(f(x)) = x^4 + 2x^3 + 2x^2 - x

3 0

2 years ago

If the simple interest on $3,000 for 4 years is $960, then what is the interest rate?

Nina [5.8K]

Answer:

8%

Step-by-step explanation:

R = 100 x I/P x t

Given

Interest I = $960

Principal P = $3000

Time t = 4 yrs

Rate R = ?

R = 100 x 960 /3000 x 4

Multiply through

R = 96000/12000

R = 8

R = 8%

8 0

2 years ago

What is the y- intercept of a line that passes through the point (1,-7) and (5, -25)

mr_godi [17]

Answer:

-32 I THINK

Step-by-step explanation:

5 0

3 years ago