  The light absorption {\cal A} and reflection{\calR} coefficients for a
three-level system in a quantum well (QW) in a strong magnetic field {\bf H},
directed perpendicularly to the QW's plane, have been calculated. The energy
levels correspond to the ground state and to magnetopolaron energy levels
\hbar\omega_{1(2)} with the inverse lifetimes \gamma_{r1(2)} and \gamma_{1(2)}.
The inverse radiative lifetime of an EHP in a QW \gamma_{r\xi}(\bf{\cal
K}_{\perp})\not=0 only under condition {\cal K}_{\perp}\le\omega_\xi n/c, where
\hbar\omega_\xi is the EHP energy. It has been shown that
\gamma_{r\xi}(\bf{\cal K}_{\perp}) is proportional to H. The values
\gamma_{ra}(\bf{\cal K}_{\perp}) and \gamma_{rb}(\bf{\cal K}_{\perp}) for an
excitation consisting of a hole and a usual magnetopolaron have been
calculated. The index a(b) designates a magnetopolaron upper (lower) term. In
the resonance at H_{res}=m_ec\omega_{LO}/|e|~~
\gamma_{ra}^{res}=\gamma_{rb}^{res}=\gamma_{r\xi_0}^{res}/2, where the index
\xi_0 corresponds to the EHP with n_e=n_h=1. The dependencies {\cal A}(H)$ and
${\cal R}(H) for various values of \omega_l in the magnetophonon resonance
vicinity have been obtained. The existence of "combined"and "weak" polarons has
been predicted. The resonant value H_{res} for the combined polaron case
depends on a QW's depth and width.
