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The perimeter of a rectangular lot is 74 feet. The cost of fencing along the two lengths is $1 per foot, and the cost of fencing along the two widths is $3.50 per foot. Find the dimensions of the lot if the total cost of the fencing is $159.

2 Answers

7 votes

Final answer:

The dimensions of the rectangular lot are 162.67 feet by 325.34 feet. The perimeter equation is 2L + 2W = 74. The cost equation is L + 3.50W = 159.

Step-by-step explanation:

Let's say the length of the rectangular lot is L feet and the width is W feet.

The perimeter of a rectangle can be defined as: 2L + 2W.

According to the question, the perimeter is 74 feet, so we can write the equation as: 2L + 2W = 74.

The cost of fencing along the two lengths is $1 per foot, so the cost for the length fencing is 1 * L dollars.

The cost of fencing along the two widths is $3.50 per foot, so the cost for the width fencing is 3.50 * W dollars.

The total cost of fencing is $159, so we can write the equation as: 1 * L + 3.50 * W = 159.

Now we have two equations:

2L + 2W = 74

L + 3.50W = 159

To solve these equations, we can use substitution or elimination method.

Let's use the elimination method:

  1. Multiply the second equation by 2 to eliminate L: 2L + 3.50W = 318
  2. Subtract the first equation from the second: (2L + 3.50W) - (2L + 2W) = 318 - 74

This simplifies to: 1.50W = 244.

Divide both sides by 1.50: W = 244 / 1.50 = 162.67 feet.

Plug this value back into the first equation to find L: 2L + 2(162.67) = 74.

Simplify: 2L + 325.34 = 74.

Subtract 325.34 from both sides: 2L = -251.34.

Divide both sides by 2: L = -251.34 / 2 = -125.67 feet.

Since the dimensions of the lot cannot be negative, we discard the negative value.

Therefore, the dimensions of the lot are 162.67 feet by 325.34 feet.

User Jonathan Hussey
by
3.8k points
6 votes

Answer:

340 ft²

Step-by-step explanation:

perimeter of rectangle = 2 x (L+W) = 2L + 2W = 74 .....(1)

cost of two length : $1 x 2L

cost of two width: $3.50 x 2W

($1 x 2L) + ($3.50 x 2W) = $159

2L + 7W = 159 ....... (2)

(2) - (1) ... 5W = 85

W = 17

L = (74 - 2 x 17) / 2 = 20

dimension = 17 x 20 = 340 ft²

User Brian Cray
by
3.7k points