6. The coffee variety Arabica yields about 750 kg of coffee beans per hectare, while Robusta yields about 1200 kg per hectare. Suppose that a plantation has a hectares of Arabica and r hectares of Robusta. Part A: Write an equation relating a and r if the plantation yields 1,000,000 kg of coffee.
Part B: On August 14, 2003, the world market price of coffee was $1.42 per kg of Arabica and $0.73 per kg of Robusta. Write an equation relating a and r if the plantation produces coffee worth $1,000,000.​