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Jonathon wants to plane a rectangular fe...

Jonathon wants to plane a rectangular fence around the border to his backyard. The width of the fence will be 350 inches more than 5 times the length of the fence. What will be the perimeter of Jonathon's fence if the area of the fence is 64,680 square inches ?

A

854 inches

B

1274 inches

C

1708 inches

D

2548 inches

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we will follow the given information and derive the necessary values to find the perimeter of Jonathon's fence. ### Step 1: Define the Variables Let: - \( L \) = Length of the fence (in inches) - \( W \) = Width of the fence (in inches) ### Step 2: Set Up the Relationship Between Width and Length According to the problem, the width is given as: \[ W = 5L + 350 \] ### Step 3: Use the Area Formula The area of a rectangle is given by the formula: \[ \text{Area} = L \times W \] We know the area is 64,680 square inches, so we can write: \[ L \times W = 64,680 \] ### Step 4: Substitute the Width in the Area Equation Substituting \( W \) from Step 2 into the area equation: \[ L \times (5L + 350) = 64,680 \] ### Step 5: Expand the Equation Expanding the left side: \[ 5L^2 + 350L = 64,680 \] ### Step 6: Rearrange the Equation Rearranging gives us: \[ 5L^2 + 350L - 64,680 = 0 \] ### Step 7: Simplify the Equation To simplify, we can divide the entire equation by 5: \[ L^2 + 70L - 12,936 = 0 \] ### Step 8: Apply the Quadratic Formula The quadratic formula is: \[ L = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] For our equation \( a = 1, b = 70, c = -12,936 \): - Calculate \( b^2 - 4ac \): \[ 70^2 - 4 \times 1 \times (-12,936) = 4900 + 51,744 = 56,644 \] Now apply the quadratic formula: \[ L = \frac{-70 \pm \sqrt{56,644}}{2 \times 1} \] ### Step 9: Calculate the Values Calculating \( \sqrt{56,644} \) gives approximately \( 238.1 \): \[ L = \frac{-70 \pm 238.1}{2} \] ### Step 10: Determine the Positive Length Calculating the two possible values for \( L \): 1. \( L = \frac{-70 + 238.1}{2} \approx \frac{168.1}{2} \approx 84.05 \) 2. \( L = \frac{-70 - 238.1}{2} \) will give a negative value, which we discard. Thus, we take: \[ L \approx 84 \text{ inches} \] ### Step 11: Calculate the Width Now substitute \( L \) back into the equation for \( W \): \[ W = 5(84) + 350 = 420 + 350 = 770 \text{ inches} \] ### Step 12: Calculate the Perimeter The perimeter \( P \) of a rectangle is given by: \[ P = 2(L + W) \] Substituting the values of \( L \) and \( W \): \[ P = 2(84 + 770) = 2(854) = 1708 \text{ inches} \] ### Final Answer The perimeter of Jonathon's fence is **1708 inches**. ---
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