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put this solution on YOUR website!If we represent length and width as L and W, respectively:
The rectangular field must have an area of at least 500sqm (to make it easier, we will use equal sign instead of the greater-than-or-equal sign:
eq1

Perimeter is 100m:
eq2

First, isolate W in eq2:

Then, substitute (50 - L) for W in eq1:

Since L > W:

Since lessening the value of L until 25 makes the area greater: