$C_A$ furniture company manufactures tables and chairs. Each table and chair must be made entirely out of oak or entirely out of pine. A total of $15,000$ board feet of oak and $21,000$ board feet of pine are available. A table requires either $17$ board feet of oak or $30$ board feet of pine, and a chair requires either $5$ board feet of oak or $13$ board feet of pine. Each table can be sold for $$800,$ and each chair for $$300.$

Formulate an algebraic model?