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The owner of an office building is expanding the length and width of a parking lot by the same amount.The lot currently measures 120 ft by 80 ft, and the expansion will increase its area by 4,400ft^2 By how many feet should the length of the parking lot be increased? 1.2 ft 20 ft 66.3 ft 220 ft

Pergunta

The owner of an office building is expanding the length and width of a parking lot by the same amount.The lot currently
measures 120 ft by 80 ft, and the expansion will increase its area by 4,400ft^2 By how many feet should the length of the
parking lot be increased?
1.2 ft
20 ft
66.3 ft
220 ft

The owner of an office building is expanding the length and width of a parking lot by the same amount.The lot currently measures 120 ft by 80 ft, and the expansion will increase its area by 4,400ft^2 By how many feet should the length of the parking lot be increased? 1.2 ft 20 ft 66.3 ft 220 ft

Solução

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MárioMestre · Tutor por 5 anos

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The length of the parking lot should be increased by 20ft.

Explicação

## Step 1<br />The problem involves the area of a rectangle, which is given by the formula:<br />### **Area = length * width**<br />The owner of the office building is expanding the parking lot by increasing both the length and the width by the same amount. Let's denote this amount as \(x\).<br /><br />## Step 2<br />The new dimensions of the parking lot will be \((120+x)\) feet by \((80+x)\) feet. The area of the expanded parking lot is given as 4,400 square feet.<br /><br />## Step 3<br />We can set up an equation to represent the area of the expanded parking lot:<br />### **(120+x) * (80+x) = 4,400**<br /><br />## Step 4<br />Expanding the left side of the equation gives us:<br />### **9,600 + 200x + x^2 = 4,400**<br /><br />## Step 5<br />Rearranging the equation to solve for \(x\) gives us:<br />### **x^2 + 200x - 5,200 = 0**<br /><br />## Step 6<br />This is a quadratic equation, which can be solved using the quadratic formula:<br />### **x = [-b ± sqrt(b^2 - 4ac)] / (2a)**<br /><br />## Step 7<br />Substituting the values of a, b, and c from our equation into the quadratic formula gives us:<br />### **x = [-200 ± sqrt((200)^2 - 4*1*(-5,200))] / (2*1)**<br /><br />## Step 8<br />Solving this equation gives us two possible values for \(x\), but since we are looking for a physical length, we only consider the positive root.
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