AREA

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A square lobby is to be tiled at Php160 per square meter. if the lobby were 2m narrower and 2m longer, the cost of tiling would be Php35,360. Find the dimension of the lobby.

(pls write the solutions.... thanks)

• AREA -

original size of lobby : x m by x m
new size = x-2 by x+2

area = (x-2)(x+2) = x^2 - 4
cost equation:

160(x^2 - 4) = 35360
x^2 - 4 = 221
x^2 = 225
x = ± 15 , but x must be positive, so

x = 15

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