Sara is serving wings and burgers at her party. Wings cost $6.00 per serving and burgers are $3.00 each. Sara knows that at least 4 of her friends want wings. Sara must spend less than $45.00. If x represents the number of wing servings and y represents the number of burgers, which system of inequalities could be used to determine how many of each kind of food Sara can serve?

For this case we have the following variables:
 x = the number of wing servings
 y = the number of burgers
 We write the system of equations:
 "Sara knows that at least 4 of her friends want wings":
 x> = 4
 "Sara must spend less than $ 45.00":
 6x + 3y <45
 Answer:
 Sara could use the following system of inequalities to determine how many of each kind of food She can serve:
 6x + 3y <45x> = 4