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प्रश्न
The length of a hall is 5 m more than its breadth. If the area of the floor of the hall is 84 m2, what are the length and breadth of the hall?
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उत्तर
Let the breadth of the rectangular hall be x meters and the length = (x + 5) meters Then
And area of the rectangle
length x breadth = 84
(x + 5)x = 84
x2 + 5x - 84 = 0
x2 - 7x + 12x - 84 = 0
x(x - 7) + 12(x - 7) = 0
(x - 7)(x + 12) = 0
x - 7 = 0
x = 7
or
x + 12 = 0
x = -12
Sides of the rectangular hall never are negative.
Therefore, length
= x + 5 = 7 + 5 = 12
Hence, breadth of the hall be 7 meters and length be 12 meters.
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