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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.
Solution
Let b be the breadth of the rectangle. then its perimeter
2( x + b ) = 70
x + b = 35
b = 35 - x
Again
`x` x b = 300
x( 35 - x ) = 300
x2 - 35x + 300 = 0
( x - 15 )( x - 20 ) = 0
x = 15, 20.
Hence its length is 20 cm and width is 15 cm.
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