The length of a 200 square foot rectangular vegetable garden is four feet less than twice the width, w. Find the length and width of the garden. Round your final answer to the nearest tenth. Do not include units.

Provide your answer below:



Answer :

Certainly! Let's solve the problem step-by-step:

1. Define the variables and the given conditions:
- Let [tex]\( w \)[/tex] be the width of the garden.
- The length of the garden is specified to be four feet less than twice the width, so we can express the length [tex]\( l \)[/tex] as:
[tex]\[ l = 2w - 4 \][/tex]
- The area of the rectangular garden is given as 200 square feet. The area [tex]\( A \)[/tex] of a rectangle is calculated as:
[tex]\[ A = l \times w \][/tex]
Substituting the given area, we get:
[tex]\[ lw = 200 \][/tex]

2. Substitute the expression for [tex]\( l \)[/tex] into the area equation:
[tex]\[ (2w - 4)w = 200 \][/tex]

3. Distribute and set up the equation:
[tex]\[ 2w^2 - 4w = 200 \][/tex]

4. Rearrange the equation into standard quadratic form:
[tex]\[ 2w^2 - 4w - 200 = 0 \][/tex]

5. To simplify, divide the entire equation by 2:
[tex]\[ w^2 - 2w - 100 = 0 \][/tex]

6. Solve the quadratic equation using the quadratic formula:
The quadratic formula is given by:
[tex]\[ w = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]
For our equation [tex]\( w^2 - 2w - 100 = 0 \)[/tex], we have [tex]\( a = 1 \)[/tex], [tex]\( b = -2 \)[/tex], and [tex]\( c = -100 \)[/tex].

Plugging these values into the quadratic formula:
[tex]\[ w = \frac{-(-2) \pm \sqrt{(-2)^2 - 4(1)(-100)}}{2(1)} \][/tex]
[tex]\[ w = \frac{2 \pm \sqrt{4 + 400}}{2} \][/tex]
[tex]\[ w = \frac{2 \pm \sqrt{404}}{2} \][/tex]
[tex]\[ w = \frac{2 \pm 2\sqrt{101}}{2} \][/tex]
[tex]\[ w = 1 \pm \sqrt{101} \][/tex]

7. Determine the feasible value for [tex]\( w \)[/tex]:
We have two potential solutions:
[tex]\[ w = 1 + \sqrt{101} \][/tex]
[tex]\[ w = 1 - \sqrt{101} \][/tex]

Since the width must be a positive value, we discard [tex]\( w = 1 - \sqrt{101} \)[/tex]. Thus:
[tex]\[ w = 1 + \sqrt{101} \][/tex]

8. Calculate the corresponding length:
Recall that the length [tex]\( l \)[/tex] is:
[tex]\[ l = 2w - 4 \][/tex]
Substituting [tex]\( w = 1 + \sqrt{101} \)[/tex]:
[tex]\[ l = 2(1 + \sqrt{101}) - 4 \][/tex]
[tex]\[ l = 2 + 2\sqrt{101} - 4 \][/tex]
[tex]\[ l = 2\sqrt{101} - 2 \][/tex]

9. Round the final answers to the nearest tenth:
- First, approximate [tex]\( \sqrt{101} \)[/tex]:
[tex]\[ \sqrt{101} \approx 10.05 \][/tex]
- Then use it to approximate [tex]\( w \)[/tex] and [tex]\( l \)[/tex]:
[tex]\[ w \approx 1 + 10.05 = 11.05 \Rightarrow \text{Rounded } w \approx 11.1 \][/tex]
[tex]\[ l \approx 2 \times 10.05 - 2 = 20.1 - 2 = 18.1 \Rightarrow \text{Rounded } l \approx 18.1 \][/tex]

Therefore, the width of the garden is approximately [tex]\( 11.1 \)[/tex] feet, and the length of the garden is approximately [tex]\( 18.1 \)[/tex] feet.