Answer:
-343
Step-by-step explanation:
Given the expression: ![\dfrac{(-7)^2}{(-7)^{-1}}](https://tex.z-dn.net/?f=%5Cdfrac%7B%28-7%29%5E2%7D%7B%28-7%29%5E%7B-1%7D%7D)
You will notice that the terms in the numerator and denominator have the same base (-7).
This makes it very easy to simplify by applying the division law of indices.
![\dfrac{a^x}{a^y} =a^{x-y}](https://tex.z-dn.net/?f=%5Cdfrac%7Ba%5Ex%7D%7Ba%5Ey%7D%20%3Da%5E%7Bx-y%7D)
Therefore:
![\dfrac{(-7)^2}{(-7)^{-1}}=(-7)^{2-(-1)}\\=(-7)^{2+1}\\=(-7)^3\\=-7 X -7 X -7\\=-343](https://tex.z-dn.net/?f=%5Cdfrac%7B%28-7%29%5E2%7D%7B%28-7%29%5E%7B-1%7D%7D%3D%28-7%29%5E%7B2-%28-1%29%7D%5C%5C%3D%28-7%29%5E%7B2%2B1%7D%5C%5C%3D%28-7%29%5E3%5C%5C%3D-7%20X%20-7%20X%20-7%5C%5C%3D-343)
Answer:
C. 31.83 feet.
Step-by-step explanation:
We have been given that Trina has $1000 to purchase an open-top cylindrical dog pen in her backyard. She wants the height of the pen to be 5 feet.
First of all, we will find the surface area of dog pen using surface area of cylinder.
,where,
r = Radius of cylinder,
h = Height of cylinder.
![\text{Surface area of cylinder}=2\pi r*5](https://tex.z-dn.net/?f=%5Ctext%7BSurface%20area%20of%20cylinder%7D%3D2%5Cpi%20r%2A5)
![\text{Surface area of cylinder}=10\pi r](https://tex.z-dn.net/?f=%5Ctext%7BSurface%20area%20of%20cylinder%7D%3D10%5Cpi%20r)
Since the area of each square foot of pen costs $1, so in $1000 Trina can cover an area of 1000 square feet.
Now, we will set the surface area of cylinder equal to 1000 to solve for the radius.
![1000=10\pi r](https://tex.z-dn.net/?f=1000%3D10%5Cpi%20r)
Upon dividing both sides of our equation by 10 pi we will get,
![\frac{1000}{10\pi}=\frac{10\pi r}{10\pi}](https://tex.z-dn.net/?f=%5Cfrac%7B1000%7D%7B10%5Cpi%7D%3D%5Cfrac%7B10%5Cpi%20r%7D%7B10%5Cpi%7D)
![31.8309886=r](https://tex.z-dn.net/?f=31.8309886%3Dr)
![r\approx 31.83](https://tex.z-dn.net/?f=r%5Capprox%2031.83)
Therefore, the radius of the dog pen is 31.83 feet and option C is the correct choice.
Y=1160-460÷80
The answer would be 8.75
Please mark me as brainliest.
Step-by-step explanation:
Find negative square root of 16. (4 points) a −4 b 4 c ±4 d −8
(10c² +49cd+49d²) ÷ (5c+7d)
(5c+7d)(2c+7d) ÷ (5c+7d)
Delete (5c+7d)
= (2c+7d)