A grocer wants to make a 10-pound mixture of peanuts and cashews that he can sell for $4.75 per pound. If peanuts cost $4.00 per pound and cashews cost $6.50 per pound, how many pounds of each should he use? Let p = pounds of peanuts and let c = pounds of cashews. Write a system of equations that could be used to solve the problem.

The first thing we will do for this case is identify variables.
 We have then:
 p = pounds of peanuts
 c = pounds of cashews
 By writing the system we have:
 c + p = 10
 4p + 6.50c = 47.5
 Whose solution is:
 c = 3
 p = 7
 Answer:
 a system of equations that could be used to solve the problem is:
 c + p = 10
 4p + 6.50c = 47.5