need help with calculus...not just answer. worked out with explanation please
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since the fence will be 3 sides, the length would be length minus 2 widths
so length = 1200 - 2x
area = length x width
width is x
area = (1200-2x)*x
= 1200x -2x^2
after doing the calculations x = 600 meters, width = 300 meters