If by "product" you mean "some function of", then yes. If you connect the voltage sources in series you will get an output voltage that is the sum of the two voltage sources. If you connect them in parallel through two equal series resistances, then the output voltage will be half-way between the two voltage source voltages.
Ok, thanks. I'm new to EE. I was just thinking about amplitude modulation. I wanted there to be a way to combine a modulating signal and a carrier signal simply by connecting their sources in a particular way.
You could use a voltage controlled oscillator, a V-F convertor. One I did used three opamps but there might be a simpler way depending on the freqs involved.
One possible way is to suppose we have an amplifier, then Vout of the amplifier is equal to Vin1 of the amplifier times the gain G of the amplifier (Vout=Vin1 * G). Now suppose the gain of the amplifier is controlled by a voltage Vin2, such that G=Vin2. Substituting Vin2 for G in the first equation gives, Vout=Vin1 * Vin2. Note that the gain of the amplifier need not be >= 1 (i.e. it could also be a voltage controlled attenuator).