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The sentence "If both its dimensions are increased by 4 m, its area is increased by 88 m^{2}." compares the area of the original rectangle to the area of a larger rectangle. The area of the original rectangle is L × W m^{2}. The larger rectangle has both dimensions increased by 4 metres so it is L + 4 metres by W + 4 metres and thus its area is (L + 4) × (W + 4) square metres. Thus the sentence "If both its dimensions are increased by 4 m, its area is increased by 88 m^{2}." says
that is
From the first sentence you can substitute L = 2 W and then solve for W. Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 