Solve for x. 13 x 18 8

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Cutting Timber. A stand of fir trees occupies 60 acres, with an average density of 200 trees per 20 acres. A forester estimates that each tree will yield 400 board-feet of lumber. Estimate the yield of the stand in board-feet if one-tenth of the trees are cut.

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Help please! The Medieval Europe How important is preservation of historical texts? How did the materials during  this time period survive? What are current methods of preservation?

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