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Question
The perimeter of a rectangular board is 70 cm. Taking its length as x cm, find its width in terms of x.
If the area of the rectangular board is 300 cm2; find its dimensions.
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Solution
Let b be the breadth of the rectangle. then its perimeter
2(x + b) = 70
x + b = 35
b = 35 - x
Again
x × b = 300
x(35 - x) = 300
35x - x2 = 300
0 = x2 - 35x + 300
(x - 15) (x - 20) = 0
x = 15, 20
Hence, its length is 20 cm and width is 15 cm.
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