We have the following:
Let c, numbers of courtside seats
let b, numbers of balcony seats
let e, numbers of endzone seats
c + b + e = 15000 (equation 1)
10c + 4b + 6e = 82000 (equation 2)
half the courtside and balcony seats and all the endzone seats are sold, the total revenue is 47000, therefore:
10*0.5c + 4*0.5b + 6e = 47000
5c + 2b + 6e = 47000 (equation 3)
Nwo, the matrix is: