Refer to the earlier problem.
Can you find all possible non zero real quadruplet(s) (P, Q, R, S) that satisfy the following system of simultaneous equations?
2*Q = P + 19/P, and:
2*R = Q + 19/Q, and:
2*S = R + 19/R, and:
2*P = S + 19/S.
Bonus Question:
In the problem given above, if the number 19 was replaced throughout by a real constant M > 1, what would have been the possible non zero real quadruplet(s) (P, Q, R, S) that satisfy the given set of equations, in terms of M?