Two sequences are defined by the system: xn=2xn−1+yn−1x_n = 2x_{n-1} + y_{n-1}xn=2xn−1+yn−1 and yn=xn−1+2yn−1y_n = x_{n-1} + 2y_{n-1}yn=xn−1+2yn−1 with x0=1x_0 = 1x0=1 and y0=1y_0 = 1y0=1. What is x2x_2x2?
555
777
999
111111