Equations Reducible to a Pair of Linear Equations in Two Variables
The perimeter...
Question
The perimeter of a rectangle is 240 cm. If its length is decreased by 10% and its breadth is increased by 20% ,we get the AZ same perimetre. Find the length,breadth of the rectangle.
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Solution
The perimeter of a rectangle is 240cm. If the length is decreased by 10% and it's breadth is increased by 20%, we get the same perimeter. Find the length and breadth of the rectangle. : Convert the new dimensions to: .9L and 1.2W : 2L + 2W = 240 Simplify, divide by 2: L + W = 120 L = 120-W; use for substitution : New dimensions 2(.9L) + 2(1.2W) = 240 Simplify divide by 2: .9L + 1.2W = 120 : Substitute (120-W) in the above equation: .9(120-W) + 1.2W = 120 108 - .9W + 1.2W = 120 .3W = 120 - 108 .3W = 12 W = 12/.3 W = 40 : Find L L = 120 - 40 L = 80