maths coursework for tommorrow

Hi Guys, New to the place, its nice isn't it...:) comfy!!... anyway just need a helping hand with the question below. i have it for coursework and i am stuck!! please help cheers!:)

The manufacturer of an electronic gadget has weekly production costs given by C=3600+100x+2x[squared] . Also, there is weekly revenue from sales of the product given by R=(500-2x)x[squared] . In both cases x denotes the number of gadgets. The producer reaches a break-even point when production costs equal the revenue, otherwise either a loss or a profit is being made. Find the number of units for which a break-even point is reached and the number of units for which maximum revenue is obtained. At this maximum, is the producer losing money or making a profit?

please help!! i haven't got a clue where to start!

That Was Great!!! but Theres One More!!!!!! help!!

thank you very much that has helped hugely!! i do have another that i need help with if your not too busy......as you were so helpful in the first place!!

A farmer has 6000ha available to plant with corn and wheat. Each hectare of corn requires 9Litres of fertilizer and 3/4hr of labour to harvest. Each hectare of wheat requires 3Litres of fertilizer and 1hr labour to harvest. The farmer only has available at most 40,500ltrs of fertilizer and at most 5250h of labour for harvesting. If x represents the number of hectares planted with corn, and y represents the number of hectares planted with wheat, write the system of linear inequalities that describes the constraints and graph the feasible region for the system. The profits per hectare are £60 for corn and £40 for wheat. Write and equation for p , the total profit. How many hectares of each crop should the farmer plant in order to maximise profit? What is the maximum profit?

any help would really be appreciated, yeah i am doing a calculus module..