Solution: Group terms: $ 9(x^2 - 2x) - 16(y^2 + 4y) = 144 $. Complete the square: $ 9[(x - 1)^2 - 1] - 16[(y + 2)^2 - 4] = 144 $. Expand: $ 9(x - 1)^2 - 9 - 16(y + 2)^2 + 64 = 144 $. Simplify: $ 9(x - 1)^2 - 16(y + 2)^2 = 89 $. The center is at $ (1, -2) $. Final answer: $oxed - Nelissen Grade advocaten