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    Question

    The length of a rectangle is 15 cm more than its width.

    If the area of the rectangle is 240 cm², what is the perimeter of the rectangle?
    A 40 cm Correct Answer Incorrect Answer
    B 50 cm Correct Answer Incorrect Answer
    C 60 cm Correct Answer Incorrect Answer
    D 70 cm Correct Answer Incorrect Answer

    Solution

    Let the width of the rectangle be x cm. Then, the length of the rectangle = x + 15 cm. Area of the rectangle = length × width = 240 cm² (x + 15) × x = 240 x² + 15x = 240 x² + 15x - 240 = 0 Solving the quadratic equation using the factorization method: (x + 24)(x - 10) = 0 So, x = 10 or x = -24. Since the width cannot be negative, x = 10 cm. Therefore, the length of the rectangle = 10 + 15 = 25 cm. Perimeter of the rectangle = 2 × (length + width) = 2 × (25 + 10) = 2 × 35 = 70 cm Correct Option: d) 70 cm

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