Benjamin€™s Backpacks can sell backpacks for $25 per backpack. The costs for making the backpacks are a fixed cost of $400 and a production cost of $15 per backpack.

(a) Write the cost and revenue equations. 

(b) Graph both equations, for up to and including 50 back-packs, on the same axes.

(c) Use the graph to estimate the number of backpacks Benjamin€™s Backpacks must sell to break even. 

(d) Write the profit formula. 

(e) Use the profit formula to determine whether Benjamin€™s Backpacks makes a profit or loss if it sells 30 back-packs. What is the profit or loss?

(f)  How many backpacks must Benjamin€™s Backpacks sell to make a profit of $1000?

Part of the question involves determining a system of equations that models the situation.