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# Maths and functions watch

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1. a piece of wire 24cm long has the shape of a rectangle. Given that the width is w cm, show that the area, A cm^2, of the rectangle is given by the function A=w(12-w)
2. Width = w, and let length = x. Therefore A=wx

Since perimeter= 2w+2x= 24,
Dividing the equation by 2, w+x=12.
Hence x=12-w

Replace the x in A=wx, thus A=w(12-w)

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Updated: October 28, 2015
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