You have to distribute the 4 to the numbers in the parenthesese. So 4 times 3x which is 12x and 4 times 5 which is 20 so now you get 12x plus 20 equals 8. Now you have to subtract 20 from 8 which is -12 so now you have 12x=-12 now divide the 12 from x and 12 from -12 and so now you have x=-1
Let the width be W, then the length is 4W (since the width is 1/4 the length)
The area of the original deck is
![W*4W=4W^{2}](https://tex.z-dn.net/?f=W%2A4W%3D4W%5E%7B2%7D%20)
The dimensions of the new deck are :
length = 4W+6
width=W+2
so the area of the new deck is :
![(4W+6)(W+2)= 4W^{2}+8W+6W+12= 4W^{2}+14W+12](https://tex.z-dn.net/?f=%284W%2B6%29%28W%2B2%29%3D%204W%5E%7B2%7D%2B8W%2B6W%2B12%3D%204W%5E%7B2%7D%2B14W%2B12)
"<span>the area of the new rectangular deck is 68 ft2 larger than the area of the original deck</span>" means that we write the equation:
![4W^{2}+14W+12=68+4W^{2}](https://tex.z-dn.net/?f=4W%5E%7B2%7D%2B14W%2B12%3D68%2B4W%5E%7B2%7D)
![14W+12=68](https://tex.z-dn.net/?f=14W%2B12%3D68)
![14W=68-12=56](https://tex.z-dn.net/?f=14W%3D68-12%3D56)
![W= \frac{56}{14}= 4](https://tex.z-dn.net/?f=W%3D%20%5Cfrac%7B56%7D%7B14%7D%3D%204%20%20)
the length is
![4W=4*4=16](https://tex.z-dn.net/?f=4W%3D4%2A4%3D16)
ft
Answer: width: 4, length: 16