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The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25