All categories

3 years ago

Find the dimension of a rectangle whose width is 10 miles less than its length and whose area is 75 square miles

Mathematics

2 answers:

cestrela7 [59]3 years ago

5 0

Answer:

The length is 15 miles and the width is 5 miles.

Step-by-step explanation:

The rectangle has two dimensions, width w and length l.

The area is given by the following formula:

$S = wl$ .

In this problem, we have that:

The width is 10 miles less than its length. This means that

$w = l - 10$

The area is 75 square miles. So

$wl = 75$

$(l - 10)l = 75$

$l^{2} - 10l - 75 = 0$ .

$l = 15$ and $l = -5$ .

We cannot have negative dimensions. This means that the length is 15 miles and the width is 5 miles.

jek_recluse [69]3 years ago

4 0

W = L - 10
75 = L × ( L - 10 )
75 = L^2 - 10L
L^2 - 10L - 75 = 0
( L - 15 ) ( L + 5 ) = 0
L = 15

w = 15 - 10
w = 5

2 dimension

You might be interested in

(t+5)(t+2),make t the subject of the formula

lianna [129]

Answer:

t= 2p+5/p-1

Step-by-step explanation:

The question is not well writen

Assume p = t+5/t-2

We are to make t the subject of the formula

Cross multiply

p(t-2) = t+5

pt - 2p = t+5

pt - t = 2p+5

t(p-1) = 2p+5

t= 2p+5/p-1

Hence the value of t is 2p+5/p-1

5 0

3 years ago

A) The equilibrium prices P1 and P2 for two goods satisfy the equations:

Allisa [31]

The value of P1 and P2 using the inverse matrix is 5 and 6 respectively.

<h3 />

The equilibrium prices of the three independent commodities using the inverse matrix are P1 = 4, P2 = 7, P3 = 8 respectively.

<h3>What is a matrix?</h3>

A matrix can be defined as a collection of integers(numbers that are either positive or negative) that are organized in rows and columns to construct a rectangular array. The numbers in this matrix system are referred to as elements.

To determine the values of P1 and P2 for the system of equations given by using an inverse matrix, we have:

9P1 + P2 = 51

3P1 +4P2 = 39

Representing the above data in matrix form, we have:

$\left[\begin{array}{cc}9&1\\3&4\\ \end{array}\right] \left[\begin{array}{c} \mathbf{P_1} \\ \mathbf{P_2}\\ \end{array}\right] = \left[\begin{array}{c} \mathbf{51} \\ \mathbf{39} \\ \end{array}\right]$ which is in the form AX = B

In order for us to determine the values of P1 and P2, Let take the inverse of A⁻¹ on both sides of the AX= B, we have:

$\mathbf{{A^{-1} AX} = A^{-1} B}$

X = A⁻¹ B

Let's start by finding A⁻¹;

$\mathbf{A = \left[\begin{array}{cc}9&1\\3&4\end{array}\right] }$

$\mathbf{A^{-1} = \dfrac{1}{36-3}\left[\begin{array}{cc}4&-1\\3&9\end{array}\right] }$

$\mathbf{A^{-1} = \dfrac{1}{33}\left[\begin{array}{cc}4&-1\\3&9\end{array}\right] }$

Now, Let's Find A⁻¹B;

$\mathbf{A^{-1}B = \dfrac{1}{33}\left[\begin{array}{cc}4&-1\\3&9\end{array}\right] \left[\begin{array}{c}51\\39\\ \end{array}\right] }$

$\mathbf{\implies \dfrac{1}{33}\left[\begin{array}{cc}204&-39\\-153&+351\end{array}\right] }$

$\mathbf{\implies \left[\begin{array}{c}\dfrac{165}{33}\\ \\ \dfrac{198}{33}\end{array}\right] }$

$\mathbf{\implies \left[\begin{array}{c}5\\ \\ 6\end{array}\right] }$

$\left[\begin{array}{c}\mathbf{P_1}\\ \mathbf{P_2}\end{array}\right]= \left[\begin{array}{c}5\\ 6 \end{array}\right] }$

Therefore, we can conclude that the value of P1 and P2 using the inverse matrix is 5 and 6 respectively.

To determine the equilibrium prices of the three independent commodities using the inverse matrix, we have:

P₁ + 2P₂ + 3P₃ = 42

2P₁ + P₂ + 4P₃ = 47

P₁ + 3P₂ + 4P₃ = 57

The matrix in AX = B form is computed as:

$\implies\left[ \begin{array}{ccc}1&2&3\\2&1&4\\1&3&4\end{array}\right] \left[\begin{array}{c}P_1\\P_2\\P_3 \end{array}\right] = \left[\begin{array}{c}42\\47\\ 57\end{array}\right]$