Answer:
![310\text{ feet and }210\text{ feet}](https://tex.z-dn.net/?f=310%5Ctext%7B%20feet%20and%20%7D210%5Ctext%7B%20feet%7D)
Step-by-step explanation:
GIVEN: A farmer has
of fencing to construct a rectangular pen up against the straight side of a barn, using the barn for one side of the pen. The length of the barn is
.
TO FIND: Determine the dimensions of the rectangle of maximum area that can be enclosed under these conditions.
SOLUTION:
Let the length of rectangle be
and
perimeter of rectangular pen ![=2(x+y)=520\text{ feet}](https://tex.z-dn.net/?f=%3D2%28x%2By%29%3D520%5Ctext%7B%20feet%7D)
![x+y=260](https://tex.z-dn.net/?f=x%2By%3D260)
![y=260-x](https://tex.z-dn.net/?f=y%3D260-x)
area of rectangular pen ![=\text{length}\times\text{width}](https://tex.z-dn.net/?f=%3D%5Ctext%7Blength%7D%5Ctimes%5Ctext%7Bwidth%7D)
![=xy](https://tex.z-dn.net/?f=%3Dxy)
putting value of ![y](https://tex.z-dn.net/?f=y)
![=x(260-x)](https://tex.z-dn.net/?f=%3Dx%28260-x%29)
![=260x-x^2](https://tex.z-dn.net/?f=%3D260x-x%5E2)
to maximize ![\frac{d \text{(area)}}{dx}=0](https://tex.z-dn.net/?f=%5Cfrac%7Bd%20%5Ctext%7B%28area%29%7D%7D%7Bdx%7D%3D0)
![260-2x=0](https://tex.z-dn.net/?f=260-2x%3D0)
![x=130\text{ feet}](https://tex.z-dn.net/?f=x%3D130%5Ctext%7B%20feet%7D)
![y=390\text{ feet}](https://tex.z-dn.net/?f=y%3D390%5Ctext%7B%20feet%7D)
but the dimensions must be lesser or equal to than that of barn.
therefore maximum length rectangular pen ![=310\text{ feet}](https://tex.z-dn.net/?f=%3D310%5Ctext%7B%20feet%7D)
width of rectangular pen ![=210\text{ feet}](https://tex.z-dn.net/?f=%3D210%5Ctext%7B%20feet%7D)
Maximum area of rectangular pen ![=310\times210=65100\text{ feet}^2](https://tex.z-dn.net/?f=%3D310%5Ctimes210%3D65100%5Ctext%7B%20feet%7D%5E2)
Hence maximum area of rectangular pen is
and dimensions are ![310\text{ feet and }210\text{ feet}](https://tex.z-dn.net/?f=310%5Ctext%7B%20feet%20and%20%7D210%5Ctext%7B%20feet%7D)
Answer:
10 miles per hour.
Step-by-step explanation:
Let x represent athlete's walking speed.
We have been given that her jogging rate is 5 mph faster than her walking rate, so athlete's jogging speed would be
miles per hour.
![\text{Distance}=\text{Rate}\cdot \text{Time}](https://tex.z-dn.net/?f=%5Ctext%7BDistance%7D%3D%5Ctext%7BRate%7D%5Ccdot%20%5Ctext%7BTime%7D)
10 minutes = 1/6 hour.
20 minutes = 1/3 hour
While walking, we will get ![D_{\text{walking}}=x\frac{\text{miles}}{\text{hour}}\cdot \frac{1}{3}\text{hour}](https://tex.z-dn.net/?f=D_%7B%5Ctext%7Bwalking%7D%7D%3Dx%5Cfrac%7B%5Ctext%7Bmiles%7D%7D%7B%5Ctext%7Bhour%7D%7D%5Ccdot%20%5Cfrac%7B1%7D%7B3%7D%5Ctext%7Bhour%7D)
![D_{\text{walking}}=\frac{x}{3}](https://tex.z-dn.net/?f=D_%7B%5Ctext%7Bwalking%7D%7D%3D%5Cfrac%7Bx%7D%7B3%7D)
While jogging, we will get ![D_{\text{jogging}}=(x+5)\frac{\text{miles}}{\text{hour}}\cdot \frac{1}{6}\text{hour}](https://tex.z-dn.net/?f=D_%7B%5Ctext%7Bjogging%7D%7D%3D%28x%2B5%29%5Cfrac%7B%5Ctext%7Bmiles%7D%7D%7B%5Ctext%7Bhour%7D%7D%5Ccdot%20%5Cfrac%7B1%7D%7B6%7D%5Ctext%7Bhour%7D)
![D_{\text{jogging}}= \frac{(x+5)}{6}](https://tex.z-dn.net/?f=D_%7B%5Ctext%7Bjogging%7D%7D%3D%20%5Cfrac%7B%28x%2B5%29%7D%7B6%7D)
Since athlete is covering same distance while walking and jogging, so we can equate both expressions as:
![\frac{x}{3}=\frac{x+5}{6}](https://tex.z-dn.net/?f=%5Cfrac%7Bx%7D%7B3%7D%3D%5Cfrac%7Bx%2B5%7D%7B6%7D)
Cross multiply:
![6x=3x+15](https://tex.z-dn.net/?f=6x%3D3x%2B15)
![6x-3x=15](https://tex.z-dn.net/?f=6x-3x%3D15)
![3x=15](https://tex.z-dn.net/?f=3x%3D15)
![\frac{3x}{3}=\frac{15}{3}\\\\x=5](https://tex.z-dn.net/?f=%5Cfrac%7B3x%7D%7B3%7D%3D%5Cfrac%7B15%7D%7B3%7D%5C%5C%5C%5Cx%3D5)
Therefore, athlete's walking speed is 5 miles per hour.
Jogging speed: ![x+5\Rightarrow 5+5=10](https://tex.z-dn.net/?f=x%2B5%5CRightarrow%205%2B5%3D10)
Therefore, athlete's jogging speed is 10 miles per hour.
Answer:
170
Step-by-step explanation:
Add 160 and 45 and 125
Then subtract it to the total number of students
So 500 minus 330
<em>3/4 is the total.</em>
<em></em>
<em></em>
<em>See attached image for explanation.</em>
<em></em>
<em>Please consider marking "Brainliest". </em>
<em></em>
<em>Thanks <3</em>
<em></em>
For this case we must find an expression equivalent to:
![x ^ 3 * y ^ {- 7}](https://tex.z-dn.net/?f=x%20%5E%203%20%2A%20y%20%5E%20%7B-%207%7D)
By definition of power properties we have to meet:
![a ^ {-1} = \frac {1} {a ^ 1} = \frac {1} {a}](https://tex.z-dn.net/?f=a%20%5E%20%7B-1%7D%20%3D%20%5Cfrac%20%7B1%7D%20%7Ba%20%5E%201%7D%20%3D%20%5Cfrac%20%7B1%7D%20%7Ba%7D)
Then, we can rewrite the expression as:
![x ^ 3 * \frac {1} {y ^ 7} =\\\frac {x ^ 3} {y ^ 7}](https://tex.z-dn.net/?f=x%20%5E%203%20%2A%20%5Cfrac%20%7B1%7D%20%7By%20%5E%207%7D%20%3D%5C%5C%5Cfrac%20%7Bx%20%5E%203%7D%20%7By%20%5E%207%7D)
Answer:
![\frac {x ^ 3} {y ^ 7}](https://tex.z-dn.net/?f=%5Cfrac%20%7Bx%20%5E%203%7D%20%7By%20%5E%207%7D)