If input x[n] = [1, 4, 7] and output is y[n] = [-1, -4], then system difference equation is ______
1
y[n] + 4y[n - 1] + 7y[n - 2] = x[n] + 4x[n - 1]
2
y[n] + 4y[n - 1] + 7y[n - 2] = -x[n] – 4x[n - 1]
3
y[n] – 4y[n - 1] – 7y[n - 2] = x[n] + 4x[n - 1]
4
-y[n] – 4y[n - 1] + 7y[n - 2] = x[n] + 4x [n - 1]