If the system of equations\( 2x+y-z=5 \)\( 2x-5y+\lambda z=\mu \)\( x+2y-5z=7 \)has infinitely many solutions, then \( (\lambda+\mu)^{2}+(\lambda-\mu)^{2} \) is equal to:
\(904\)
\(912\)
\(916\)
\(920\)