While at a bakery, Lester decides to purchase some cupcakes and brownies to share with his friends. He can spend up to $18, and the bakery charges $2 for a cupcake and $1 for a brownie. To ensure that he has enough food,
Lester wants to buy at least 7 cupcakes and brownies. Select the system of inequalities that describes this situation.
Use the given numbers and the following variables.
x the number of cupcakes
y the number of brownies