.
x acres for corn;
y acres for wheat;
z acres for soybeans.
The profit function
P(x,y,z) = 30x + 20y + 20z (1) (= objective function)
Restrictions:
x + y + z <= 1000 (2) (1000 acres in all)
100x + 120y + 70z <= 100000 (3) (cost for preparation)
7x + 10y + 8z <= 8000 (4) (man-days work)
x >= 0, y >= 0, z >= 0 (5) (standard non-negativity restrictions)
Now go to the site https://www.zweigmedia.com/RealWorld/simplex.html
https://www.zweigmedia.com/RealWorld/simplex.html
and use the free of charge solver there.
Input the profit function and the restrictions and press the "Solve" button.
It will solve this maximization problem using the Linear Programming method.
The solver produces this solution (this answer)
X = 1000 acres; Y = 0 acres; Z = 0 acres; p = 30000. ANSWER
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My input to the solver is shown/presented/documented below :
Maximize p = 30x + 20y + 20z subject to
x + y + z <= 1000
100x + 120y + 70z <= 100000
7x + 10y + 8Z <= 8000
x >= 0
y >= 0
z >= 0
For reliability purposes, I checked this solution by running another solver,
https://www.wolframalpha.com/widgets/view.jsp?id=daa12bbf5e4daec7b363737d6d496120
and obtained the same result.