How do you express amplitude, frequency and phase modulation?

Which is more advantageous: amplitude modulation or frequency modulation ?

A: The bandwidth of a modulated signal is 2f_(m) in amplitude modulation, where f_(m) is the frequency of the modulating signal. R: In case of amplitude modulation the frequency of a modulated signal is equal to the frequency of the carrier wave.

A sinusoidal carrier voltage of 80 volts amplitude and I MHz frequency is amplitude modulated by a sinusoidal voltage of frequency 5kHz producing 50% modulation. Calculate the amplitude and frequency of lower and upper side bands.