Linear Equations-algebraic method-eleventh grade-5
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The length of a hall is twice its breadth. If both the length and the breadth be increased by 2 meters,
the area of the hall will increase by 52 sq. meters. Find the area of the hall.
Solution: Let the breadth be x meters. Then length is 2x meters.
Area = l X b
= (2x)x = 2x2 sq. meters.
(x + 2)(2x + 2) = 2x2 + 52
i.e. 2x2 + 6x + 4 = 2x2 + 52
Therefore, 6x + 4 = 52
i.e. 6x = 52 – 4 = 48
Therefore, x = 48 / 6 = 8
Area = 2x2 = 2 (8)2 = 128 sq. meters.
