The question is the maximum value of a binary function, and the answer can be seen as follows:

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This is a linear program problem in optimization,

Generally speaking, the standard form of this kind of question is:

1.？ Goal: max? z=？ 10x？ +? 9y？ -? (cost)

2. Constraints:? The amount of raw materials consumed by each pencil and the total amount of raw materials.

Please give the original question,

Then we can list the linear programming equations,

Solved by simplex method.