A website that sells songs for downloading has two different price categories. Older songs are $0.99 and new releases are $1.29. Macy spent $15.36 downloading songs during the month. She downloaded a total of 9 songs. Write a system of equations that represents the situation where x is the number of songs Macy downloaded at $0.99 and y is the number of songs she downloaded at $1.29. You do not need to solve the equations.