Find the explicit formula for the solution to the following linear iterative systems: (a) u(k+1) = u(k)

Question:

Find the explicit formula for the solution to the following linear iterative systems:
(a) u(k+1) = u(k) - 2v(k), v(k+1) = - 2u(k) + v(k), u(0) = 1, v(0) = 0
(b) u(k+1) = u(k) - 2/3 v(k), v(k+1) = 1/2u(k) + 1/6 v(k), u(0) = -2, u(0) = 3
(c) u(k+1) = u(k) - v(k), v(k+1) = -u(k) + 5v(k), u(0) = 1, v(0) = 0
(d) u(k+1) = 1/2 u(k) + v(k), v(k+1) = v(k) - 2w(k),
w(k+1) = 1/3 w(k) = 1, v(0) = -1, w(0) = 1
(e)