ANSWER
![3 {x}^{2} y \sqrt[4]{y}](https://tex.z-dn.net/?f=3%20%7Bx%7D%5E%7B2%7D%20y%20%5Csqrt%5B4%5D%7By%7D%20)
EXPLANATION
We want to simplify:
![\sqrt[4]{81 {x}^{8} {y}^{5} }](https://tex.z-dn.net/?f=%20%5Csqrt%5B4%5D%7B81%20%7Bx%7D%5E%7B8%7D%20%7By%7D%5E%7B5%7D%20%20%7D%20)
We can split the radical sign to obtain:
![\sqrt[4]{81} \times \sqrt[4]{ {x}^{8} } \times \sqrt[4]{ {y}^{5} }](https://tex.z-dn.net/?f=%20%5Csqrt%5B4%5D%7B81%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7Bx%7D%5E%7B8%7D%20%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7By%7D%5E%7B5%7D%20%7D%20)
Or
![\sqrt[4]{81} \times \sqrt[4]{ {x}^{8} } \times \sqrt[4]{ {y}^{4} \times y}](https://tex.z-dn.net/?f=%20%5Csqrt%5B4%5D%7B81%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7Bx%7D%5E%7B8%7D%20%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7By%7D%5E%7B4%7D%20%20%5Ctimes%20y%7D%20)
![\sqrt[4]{81} \times \sqrt[4]{ {x}^{8} } \times \sqrt[4]{ {y}^{4}} \times \sqrt[4]{y}](https://tex.z-dn.net/?f=%20%5Csqrt%5B4%5D%7B81%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7Bx%7D%5E%7B8%7D%20%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7By%7D%5E%7B4%7D%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7By%7D%20)
![\sqrt[4]{ {3}^{4} } \times \sqrt[4]{ {x}^{8} } \times \sqrt[4]{ {y}^{4}} \times \sqrt[4]{y}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B%20%7B3%7D%5E%7B4%7D%20%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7Bx%7D%5E%7B8%7D%20%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7B%20%7By%7D%5E%7B4%7D%7D%20%20%5Ctimes%20%20%5Csqrt%5B4%5D%7By%7D%20)
Recall that:
![\sqrt[n]{ {a}^{m} } = {a}^{ \frac{m}{n} }](https://tex.z-dn.net/?f=%20%5Csqrt%5Bn%5D%7B%20%7Ba%7D%5E%7Bm%7D%20%7D%20%20%3D%20%20%7Ba%7D%5E%7B%20%5Cfrac%7Bm%7D%7Bn%7D%20%7D%20%20)
![{3}^{4 \times \frac{1}{4} } \times {x}^{8 \times \frac{1}{4} } \times {y}^{4 \times \frac{1}{4} }\times \sqrt[4]{y}](https://tex.z-dn.net/?f=%7B3%7D%5E%7B4%20%5Ctimes%20%20%5Cfrac%7B1%7D%7B4%7D%20%7D%20%20%5Ctimes%20%20%7Bx%7D%5E%7B8%20%5Ctimes%20%20%5Cfrac%7B1%7D%7B4%7D%20%20%7D%20%20%5Ctimes%20%20%7By%7D%5E%7B4%20%5Ctimes%20%20%5Cfrac%7B1%7D%7B4%7D%20%7D%5Ctimes%20%20%5Csqrt%5B4%5D%7By%7D%20)
![3 {x}^{2} y \sqrt[4]{y}](https://tex.z-dn.net/?f=3%20%7Bx%7D%5E%7B2%7D%20y%20%5Csqrt%5B4%5D%7By%7D%20)
Area of rectangle = length × width
300 = (x+10) × x
300 = 10x + x^2
Now we have the equation y=x^2 + 10x - 300
We can factor this equation to get our zeroes, which are:
-5(1+sqrt(13)),
5(sqrt(13)-1)
We only use the positive zero because we can't have a negative dimension.
Your width would be:
5(sqrt(13)-1)
Your length would be:
5(sqrt(13)-1) + 10
<h2>
<u>Answer</u> :-</h2>
To find the cost of planting grass , we have to find area of the field.
Area of field = Length × Breadth


Now convert into hectare.
1 hectare = 10000m sq.
51000 / 10000
So area field = 5.1 hectare sq.
Now cost = 5.1 x 0.80 p

<h2>
<u>___________</u></h2>
Answer:
This can be shown as an inequality. A quick way to calculate upper and lower bands is to halve the degree of accuracy specified, then add this to the rounded value for the upper bound, and subtract it from the rounded value for the lower bound.
I hope it's helpful!