The restaurant bill you and your friend received was not itemized. you ordered 2 drink refills and the egg breakfast, for a total of $8.40. your friend ordered 3 refills and the egg breakfast for $9.35. (a) write a system of equations for the situation. use r for the amount charged for a refill and b for the amount charged for the egg breakfast. (b) graph the equations in the system. (c) use your graph to estimate how much each item cost.