Answer:
The Dimension of new garden is ![25 \ feet\ \times 10\ feet.](https://tex.z-dn.net/?f=25%20%5C%20feet%5C%20%5Ctimes%2010%5C%20feet.)
Step-by-step explanation:
Given:
Perimeter of new garden = 70 feet.
Let the length of the new garden be 'l'.
Also Let the width of the new garden be 'w'.
We need to find the dimension of new garden.
Now Given:
Length is 5 feet shorter than three times it width.
framing the equation we get;
![l =3w-5 \ \ \ \ equation\ 1](https://tex.z-dn.net/?f=l%20%3D3w-5%20%5C%20%5C%20%5C%20%5C%20equation%5C%201)
Now we know that;
Perimeter of rectangle is equal to twice the sum of length and width.
framing in equation form we get;
![2(l+w)=70](https://tex.z-dn.net/?f=2%28l%2Bw%29%3D70)
Now Diving both side by 2 using Division property of equality we get;
![\frac{2(l+w)}2=\frac{70}{2}\\\\l+w =35](https://tex.z-dn.net/?f=%5Cfrac%7B2%28l%2Bw%29%7D2%3D%5Cfrac%7B70%7D%7B2%7D%5C%5C%5C%5Cl%2Bw%20%3D35)
Now Substituting equation 1 in above equation we get;
![3w-5+w=35\\\\4w-5=35](https://tex.z-dn.net/?f=3w-5%2Bw%3D35%5C%5C%5C%5C4w-5%3D35)
Adding both side by 5 Using Addition Property of equality we get'
![4w-5+5=35+5\\\\4w=40](https://tex.z-dn.net/?f=4w-5%2B5%3D35%2B5%5C%5C%5C%5C4w%3D40)
Now Diving both side by 4 using Division property of equality we get;
![\frac{4w}{4}=\frac{40}{4}\\\\w=10\ ft](https://tex.z-dn.net/?f=%5Cfrac%7B4w%7D%7B4%7D%3D%5Cfrac%7B40%7D%7B4%7D%5C%5C%5C%5Cw%3D10%5C%20ft)
Now Substituting the value of 'w' in equation 1 we get;
![l =3w-5\\\\l =3\times10-5\\\\l = 30-5\\\\l= 25\ ft](https://tex.z-dn.net/?f=l%20%3D3w-5%5C%5C%5C%5Cl%20%3D3%5Ctimes10-5%5C%5C%5C%5Cl%20%3D%2030-5%5C%5C%5C%5Cl%3D%2025%5C%20ft)
Hence The Dimension of new garden is ![25 \ feet\ \times 10\ feet.](https://tex.z-dn.net/?f=25%20%5C%20feet%5C%20%5Ctimes%2010%5C%20feet.)