Minimizing Cost

A gentleman has bought a rectangular piece of land whose perimeter is to be 100 rods; and he is to pay 1 dollar for each rod in the length of the land and 3 dollars for each rod in the breath of the land.  It is required to determine the length and breadth so that the quantity of land may be had at the cheapest price possible.

The Mathematical Correspondent, Volume 1, 1804

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