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3 years ago

Jason is three roommates share the cost of the electric bill $108 evenly

Mathematics

1 answer:

I am Lyosha [343]3 years ago

4 0

Its $36 if it is only for his three roommates
and
$27 if it is only for his three roommates w/ Jason

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The length of a rectangular garden is 17 feet longer than its width. If the area of the garden is 234 square feet, what are the

kifflom [539]

Answer:

The garden is 9 feet wide and 26 feet long.

Step-by-step explanation:

L = W+17

area = LW = 234

(W+17)W = 234

W²+17W-234 = 0

Quadratic formula

W = [-17 ± √(17² – 4·1(-234))] / [2·1]

= [-17 ± √1225] / 2

= [-17 ± 35] /2

= -26, 9

-26 is an extraneous solution

W = 9

L = W+17 = 26

The garden is 9 feet wide and 26 feet long.

3 0

2 years ago

What is the answer to the fraction 2 ⅓+⅚=

kramer

Answer:

Step-by-step explanation:

$2 \frac {1}{3}+\frac{5}{6}\\=\frac{7}{3}+\frac{5}{6}\\=\frac{14+5}{6}\\=\frac{19}{6}\\=3 \frac{1}{6}$

8 0

2 years ago

Read 2 more answers

A player on a school baseball team reaches first base 3/10 of the time he is at bat.Out of 80 times at bat,about how many times

Cerrena [4.2K]

Set up a proportion: 3/10= x/80. Then if you multiply 10 by 8, you get 80 on both sides, But, If you do it to the top, you also have to do it to the bottom, so the anser is 3 x 8 , or 24.

3 0

3 years ago

Read 2 more answers

EXAMPLE 5 Find the maximum value of the function f(x, y, z) = x + 2y + 11z on the curve of intersection of the plane x − y + z =

Taya2010 [7]

Answer:

$\displaystyle x= -\frac{10}{\sqrt{269}}\\\\\displaystyle y= \frac{13}{\sqrt{269}}\\\\\displaystyle z = \frac{23\sqrt{269}+269}{269}$

<em>Maximum value of f=2.41</em>

Step-by-step explanation:

<u>Lagrange Multipliers</u>

It's a method to optimize (maximize or minimize) functions of more than one variable subject to equality restrictions.

Given a function of three variables f(x,y,z) and a restriction in the form of an equality g(x,y,z)=0, then we are interested in finding the values of x,y,z where both gradients are parallel, i.e.

$\bigtriangledown f=\lambda \bigtriangledown g$

for some scalar $\lambda$ called the Lagrange multiplier.

For more than one restriction, say g(x,y,z)=0 and h(x,y,z)=0, the Lagrange condition is

$\bigtriangledown f=\lambda \bigtriangledown g+\mu \bigtriangledown h$

The gradient of f is

$\bigtriangledown f=$

Considering each variable as independent we have three equations right from the Lagrange condition, plus one for each restriction, to form a 5x5 system of equations in $x,y,z,\lambda,\mu$ .

We have

$f(x, y, z) = x + 2y + 11z\\g(x, y, z) = x - y + z -1=0\\h(x, y, z) = x^2 + y^2 -1= 0$

Let's compute the partial derivatives

$f_x=1\ ,f_y=2\ ,f_z=11\ \\g_x=1\ ,g_y=-1\ ,g_z=1\\h_x=2x\ ,h_y=2y\ ,h_z=0$

The Lagrange condition leads to

$1=\lambda (1)+\mu (2x)\\2=\lambda (-1)+\mu (2y)\\11=\lambda (1)+\mu (0)$

Operating and simplifying

$1=\lambda+2x\mu\\2=-\lambda +2y\mu \\\lambda=11$

Replacing the value of $\lambda$ in the two first equations, we get

$1=11+2x\mu\\2=-11 +2y\mu$

From the first equation

$\displaystyle 2\mu=\frac{-10}{x}$

Replacing into the second

$\displaystyle 13=y\frac{-10}{x}$

Or, equivalently

$13x=-10y$

Squaring

$169x^2=100y^2$

To solve, we use the restriction h

$x^2 + y^2 = 1$

Multiplying by 100

$100x^2 + 100y^2 = 100$

Replacing the above condition

$100x^2 + 169x^2 = 100$

Solving for x

$\displaystyle x=\pm \frac{10}{\sqrt{269}}$

We compute the values of y by solving

$13x=-10y$

$\displaystyle y=-\frac{13x}{10}$

For

$\displaystyle x= \frac{10}{\sqrt{269}}$

$\displaystyle y= -\frac{13}{\sqrt{269}}$

And for

$\displaystyle x= -\frac{10}{\sqrt{269}}$

$\displaystyle y= \frac{13}{\sqrt{269}}$

Finally, we get z using the other restriction

$x - y + z = 1$

Or:

$z = 1-x+y$

The first solution yields to

$\displaystyle z = 1-\frac{10}{\sqrt{269}}-\frac{13}{\sqrt{269}}$

$\displaystyle z = \frac{-23\sqrt{269}+269}{269}$

And the second solution gives us

$\displaystyle z = 1+\frac{10}{\sqrt{269}}+\frac{13}{\sqrt{269}}$

$\displaystyle z = \frac{23\sqrt{269}+269}{269}$

Complete first solution:

$\displaystyle x= \frac{10}{\sqrt{269}}\\\\\displaystyle y= -\frac{13}{\sqrt{269}}\\\\\displaystyle z = \frac{-23\sqrt{269}+269}{269}$

Replacing into f, we get

f(x,y,z)=-0.4

Complete second solution:

$\displaystyle x= -\frac{10}{\sqrt{269}}\\\\\displaystyle y= \frac{13}{\sqrt{269}}\\\\\displaystyle z = \frac{23\sqrt{269}+269}{269}$

Replacing into f, we get

f(x,y,z)=2.4

The second solution maximizes f to 2.4

5 0

3 years ago

Bob wants to put down new sod in his backyard except for the part set aside for his flower garden the diagram shows bobs backyar

zmey [24]

Answer:

Bob will need $235\ yd^{2}$ of sod

Step-by-step explanation:

step 1

Find the area of the backyard

$A=20(14)=280\ yd^{2}$

step 2

Find the area of the flower garden

$A=5(9)=45\ yd^{2}$

step 3

Find the difference

$280\ yd^{2}-45\ yd^{2}=235\ yd^{2}$

0 0

3 years ago