Answer:
- width -- 10 ft
- length -- 35 ft
Step-by-step explanation:
We can let x represent the width. Then the length will be represented by (3x+5), a value 5 more than 3 times the width.
The area is the product of length and width, so is ...
A = (3x +5)(x) = 3x^2 +5x
To make the area 350, we can find the value of x from ...
3x^2 +5x = 350
This can be solved a number of ways. One of them is "completing the square".
3(x^2 +5/3x) = 350
We choose to divide by 3 and add the square of half the x-coefficient.
x^2 +5/3x +(5/6)^2 = (350/3) + (5/6)^2
(x +5/6)^2 = 4225/36 . . . . simplify
x +5/6 = ±√(4225/36) = ±10 5/6 . . . . take the square root
x = 10 or -11 2/3 . . . . subtract 5/6
The positive solution is the one of interest: x = 10.
The driveway is 10 ft wide and 35 ft long.
![( \sqrt[n]{a} ) ^{m} =( a^{ \frac{1}{n}} )^{m} = a^{ \frac{1}{n}*m}=a^{ \frac{m}{n}}](https://tex.z-dn.net/?f=%28%20%20%5Csqrt%5Bn%5D%7Ba%7D%20%20%29%20%5E%7Bm%7D%20%3D%28%20a%5E%7B%20%5Cfrac%7B1%7D%7Bn%7D%7D%20%29%5E%7Bm%7D%20%3D%20a%5E%7B%20%5Cfrac%7B1%7D%7Bn%7D%2Am%7D%3Da%5E%7B%20%5Cfrac%7Bm%7D%7Bn%7D%7D)
, and compare them to each other.
![( \sqrt[3]{125} ) ^{7} =( 125^{ \frac{1}{3}} )^{7} = 125^{ \frac{1}{3}*7}= 125^{ \frac{7}{3}}](https://tex.z-dn.net/?f=%28%20%20%5Csqrt%5B3%5D%7B125%7D%20%29%20%5E%7B7%7D%20%3D%28%20125%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%7D%20%29%5E%7B7%7D%20%3D%20125%5E%7B%20%20%5Cfrac%7B1%7D%7B3%7D%2A7%7D%3D%20125%5E%7B%20%5Cfrac%7B7%7D%7B3%7D%7D%20%20%20)
