Where do I start if I need to make a scematic to create a circuit that has a 100 ohm resistor and it gives 3 1/2 volts - plus or minus 5%. I can use as many 1.5 volt batteries as needed.

Are there no other components?

Where do I start if I need to make a scematic to create a circuit that has a 100 ohm resistor and it gives 3 1/2 volts - plus or minus 5%. I can use as many 1.5 volt batteries as needed.

That is problematic since it may be hard to find 1.5 volt batteries that are +/- 5% to begin with. It is also not clear if you are saying that you can only use one resistor or more than one. If more than one, I would use 3 batteries and a voltage divider circuit on the third battery using the resistors to bring it down to a half volt, and then put the three in series to give me 3.5 volts.